This is a full Mirror Glaze Galaxy Cake tutorial showing how to make colorful galaxy cake pop planets, galaxy cake batter, galaxy vanilla buttercream, and galaxy mirror glaze. By the way, have you seen my Pink and White Cake with red hearts?
Step-by-step video tutorial
How to Make Cake Pop Planets
Food coloring
I use the following colors for the cake pops: yellow, red, green, navy blue, purple, white, and Aztec blue (teal tone).
I chose to make the Sun, Earth, Uranus, and Neptune for this recipe. I use yellow and red for the Sun, green and blue (and white if desired) for the Earth, teal and white for Uranus, and purple with white for Neptune.
Add as much food coloring as described on the package until you reach the desired color. You can use gel or paste food coloring.
Tip: Additionally, I add a bit of white food coloring to every color to brighten up the color of the batter.
Cake pop mold
I recommend using a silicone cake pop mold to bake the planets. Alternately spoon the colored batter into the mold, making a few swirls with the tip of a knife or toothpick. Fill up until slightly heaped.
Tips for Making the Cake Batter
Note: I chose a white cake for this recipe because it's a very light batter and perfect for coloring but you can use your favorite vanilla cake as well.
Divide the cake batter into 4 bowls (2 large bowls and 2 small bowls). Add black food coloring in one of the large bowls, white in the other, pink in one of the small bowls, and aztec blue in the other small bowl. Stir until evenly colored.
Alternately, spoon about ¼ of the colored batter into two 8" (20cm) cake pans just until the bottom is fully covered. Arrange the baked cake pops on top of the batter in the two cake pans. Spoon the remaining batter on top of the planets to cover them completely. Then carefully run the tip of a knife through the batter to draw a pattern. Be careful not to mix up the colors too much.
Notes on the buttercream
The buttercream is regular vanilla buttercream with food coloring. Be sure to use a food coloring that's suitable for cake batters, buttercreams, icing, and icing. I recommend using gel or paste food coloring.
Divide the buttercream between 4 bowls and tint with black, blue, white and pink. Spoon the colored buttercream alternately into a piping bag or onto the cake and frost the cake with an offset spatula.
Tips for frosting the cake
- Be careful not to mix the colors too much while frosting the cake.
- Freeze the cake uncovered for 1 hour, until the buttercream is very firm. This will ensure your frosting doesn't melt while applying the mirror glaze.
How to Successfully Make a Mirror Glaze
The mirror glaze is the most challenging part of the recipe. But don't worry; I have a few recommendations on what to do before you tackle the glaze.
- Watch the video. Familiarize yourself with the process by watching the video multiple times and thinking the process through in your head. Analyze what you see, how I apply the glaze, what the consistency of the glaze is, etc.
- Plan and prepare everything in advance. Read the directions carefully to have all the ingredients and tools ready when you need them.
- Use a food thermometer. It's an invaluable investment and gives you peace of mind that the glaze is at the right temperature to be neither too thick nor too thin.
Colors needed for the mirror glaze
Divide the mirror glaze among 5 bowls. 2 large bowls and 3 smaller bowls. Add aztec blue and navy blue in a 3:1 ratio in either of the two large bowls. In the second large bowl, add black and navy blue in a 1:1 ratio until you have a very dark shade of blue.
Then add a little pink food coloring to one of the small bowls, purple to the second bowl, and aztec (teal) blue to the last bowl. Add some white if any of the colors have become too intense or too dark.
How to apply the mirror glaze
- Line a cookie or baking sheet with parchment paper and place a vase upside down in the center of the sheet. Make sure the diameter of the vase or jar you use is smaller than the cake. Then place the cake on top.
- The glaze must be 90°F / 32°C so that it is neither too thin nor too thick. If your frosting is too hot, let it sit until it has cooled slightly. Otherwise the frosting will not stick to your cake and will be too runny. If the frosting is too cold, it will be too sticky and you won't be able to pour it over your cake. In this case, heat in the microwave for a few seconds.
- Pour the aztec/navy glaze into the black/navy glaze and carefully draw in a few swirls without mixing the colors. Pour the glaze over the cake, starting in the center and moving the bowl in a circular motion to the edges of the cake while pouring and let drip over the sides until the cake is fully glazed.
- Using small spoons, pour lines of the teal, purple, and pink glaze onto the cake. Finish the pattern by gently stroking the top of the cake with the large offset spatula. I recommend working the spatula in the direction of the lines on the cake for the most beautiful effect.
- Sprinkle some black pearl dust on top of the cake and spritz small drops of white food coloring on top with a brush for the perfect finish.
FAQs
Yes, the cake planets are baked twice. Although I don't find the cake pops too dry, they are definitely not moist after baking them twice.
Yes absolutely. Feel free to use your favorite vanilla cake recipe instead of the white cake batter used in this recipe.
You can bake and frost the cake ahead of time and refrigerate until ready to serve. However, I recommend glazing the cake the day you serve it, as the mirror glaze loses its perfect shine over time.
More Celebration Cakes to Try
Recipe
Mirror Glaze Galaxy Cake Recipe
Ingredients
Galaxy Cake Pop Planets
- 3 large eggs
- ½ cup granulated white sugar
- ½ cup unsalted butter, at room temperature
- 1 cup all-purpose flour, spooned and leveled
- ½ teaspoon baking powder
- ¼ teaspoon salt
Galaxy Cake
- 1 cup milk, room temperature
- 6 large egg whites, room temperature
- 2 ¼ cups all-purpose flour, spooned and leveled
- 4 teaspoon baking powder
- ½ teaspoon salt
- ¾ cup unsalted butter, at room temperature
- 1 ¼ cups granulated white sugar
- 1 vanilla bean* (or 1 teaspoon vanilla extract)
Galaxy Vanilla Buttercream
Galaxy Mirror Glaze
- ¾ cup cold water
- 1.25 oz powdered gelatin
- 12 oz white couverture chopped
- 1 ½ cups granulated white sugar
- ⅜ cup water
- ¾ cup light corn syrup
- ¾ cup sweetened condensed milk
Instructions
Galaxy Cake Pop Planets
- Microwave butter for about 15-20 seconds until very soft and a bit melted. Set aside.
- Preheat oven to 350°F / 175°C.
- With a handheld or stand mixer fitted with a whisk or paddle attachment, mix eggs on medium-high speed until combined for about 1 minute. Add sugar and mix until light and creamy for about 2-3 minutes. Add butter and mix until creamy. In the end, add flour, baking powder, and salt and mix until fully combined and smooth.
- If you want to make the same planets like me, separate batter in 6 bowls and color with navy blue, purple, green, Aztec blue (teal tone), yellow, red, and white. Use gel or paste food coloring. Depending on your food coloring brand, add a few drops to your batter until you reach the desired color. If you want to use more of one color and less of another, consider the required amount of batter per color while separating into bowls. I added to every portion a bit of white to lighten up the colors.
- Use a 20 cake pop mold. Spoon red and yellow batter into a few mold for the sun (the side of the mold without the holes). Blue and green (with a bit of white if desired) for the Earth, teal with a bit of white for Uranus, and purple with a bit of white for Neptune. Fill until level with a very slightly heaping and draw a few swirls with a skewer. Place the second side of the cake pop mold on top (the one with the hole) and close tightly. Bake for about 18-20 minutes. I baked mine for 20 minutes. Let cool in the mold until you are done with the cake batter. Set aside.
Galaxy Cake
- Line two 8-inch baking pans with parchment paper by cutting 8-inch circles for the bottom and about 2-3 inch wide strips for the sides. Use very less baking spray underneath the paper that it sticks to the pan for easier filling.
- In a small bowl, whisk milk and egg whites until combined. Set aside.
- In another small bowl combine flour, baking powder, and salt and stir to combine. Set aside.
- With a handheld or stand mixer fitted with a whisk or paddle attachment mix butter and sugar on medium speed until creamy and combined for about 1-2 minutes. Add vanilla* and mix until combined. Mixing on low speed, alternately add dry and wet mixtures, beginning and ending with dry ingredients. I added the dry ingredients in 3 batches and the wet ingredients in 2. Mix until smooth and combined.
- I used 4 colors for the galaxy cake batter. Black, white, pink, and Aztec blue (teal tone). Divide batter into 2 big and 2 small bowls. Add black food coloring and white food coloring in the two big bowls and pink and a bit of Aztec blue in the two small bowls. Add white if you want to lighten up the colors.
- Spoon about ¼ of the colored batter alternately in the two pans equally until the bottom is covered. Gently draw a pattern. Be careful that you don't mix up the colors. Place 10 cake pops planets in each pan. Spoon remaining batter on top of the planets. Bake for about 27-30 minutes until a toothpick centered in the middle comes out clean (don't pick inside a cake pop). Let cool in pans for about 10 minutes then transfer to a wire rack to cool completely.
Galaxy Vanilla Buttercream
- Mix butter with a whisk attachment on medium speed until creamy for about 2 minutes. Add 1 cup sugar at the time and mix on low speed until combined. Add salt and mix to combine. Mix in vanilla* and milk until smooth and fully incorporated. Divide buttercream into 4 bowls. I used black, white, blue, and pink. Add white to lighten up the colors if desired. Spoon the colored buttercream alternately into a piping bag.
Frost the cake
- Place bottom cake layer with a cake board underneath on a turner. Pipe a thin layer of buttercream on top. Even with a big offset spatula by placing the edge of the spatula on top of the cream horizontally and spin the cake around. Place the second cake layer on top. Pipe remaining buttercream on top and the sides until the cake is fully covered. Level the top with the spatula like you did with the bottom cake layer until buttercream is smooth and even.
- To level the buttercream on the sides, plant the spatula next to one side uprightly and spin the cake around. Take care that you keep the same angle while spinning the cake around. Smooth the edges by leveling the top again and push frosting very slightly and carefully to the edges. Then level the edges on the sides again and repeat until edges are smoothed.
- Freeze cake with the board underneath for about 1 hour that the buttercream is very firm and doesn't melt away while glazing.
Galaxy Mirror Glaze
- Add ¾ cup of water and gelatin in a small bowl and stir to combine. Let bloom for about 10 minutes. It needs to be firm to touch.
- Place chopped couverture in a big bowl and set aside.
- In a small saucepan bring sugar, ⅜ cup water, and corn syrup over medium heat to a boil and simmer for about 2-3 minutes. Remove from stove and stir in bloomed gelatin and condensed milk until combined. Pour over couverture, cover with a towel and let stand for about 2 minutes.
- Mix with a handheld emersion blender until smooth, and no lumps remain. Strain and separate mirror glaze in 5 bowls. Two big ones, and 3 smaller ones. Add Aztec blue and navy blue in a 3:1 ratio in one big bowl. Add black and navy blue in equal amounts to the second big bowl. In the 3 small bowls, add purple, pink, and Aztec blue (teal tone). Add white to brighten up the colors if needed.
Glaze the cake
- Line a cookie or baking sheet with parchment paper. Place a vase upside down in the middle. Remove cake from the freezer and place on top of the vase.
- The mirror glaze needs to be 90°F / 32°C while glazing that it is not too thin and not too thick. Use a candy thermometer. When your glaze is too hot, let it stand until it cools down a bit. This will go very fast. Otherwise, the glaze doesn’t stick to your cake and is too runny. When the glaze is too cold, it is too sticky, and you can’t pour it over your cake. In this case, warm it up in the microwave for a few seconds.
- Pour the blue from the first big bowl into the very dark space blue in the second big bowl. Give it a few gentle swirls and draw a pattern. Don't mix up the colors. Pour over cake beginning on the top and then let drip over the sides until the cake is fully glazed. Drip with a spoon a few lines of teal, purple, and pink on top. Go with the lines of the light and dark blue pattern.
- Brush with a big offset spatula over the top of the cake to smooth the colors. Sprinkle a bit of black pearl dust and white food coloring on top of the cake with a brush.
- Let dry for about ½ hour then transfer to the fridge and chill for 2 hours. Cut cake with a very warm knife (warm with hot water then dry) for best cutting results. Store leftovers in an airtight container in the fridge up to 3 days.
Notes
Video
You can find the video in the post above. If you don't see a video, please check your browser settings.
Mia
Hi Sabine, thanks for sharing this! I’m excited to try this for my son’s birthday. I have a question about the butter you’ve included: does this recipe use unsalted or salted butter? Thanks!
Sabine
Hi Mia, I use unsalted butter for this recipe. Good luck!
Louise
Can you advise which flour you use, is it plain or self raising?
Sabine
Plain flour is what I used.
Louise
I’ve baked the cake but would like to freeze it until I want to glaze it in about a week will this be ok?
Thanks
Sabine
Yes, absolutely.
Louise
Also I’m unable to buy corn syrup can you recommend an alternative please?
Sabine
I'm sorry, unfortunately, corn syrup is an essential ingredient for the fluidity of the glaze.
Mandy
Did you bake your cake pops until they were completely done or a little underdone? I read another recipe/post where the baker left the cake pops a bit undercooked then froze them so they wouldn’t be too dry or over baked when added to the main cake. Does it make a big difference?
Sabine
I baked them until they were completely done, but you can bake them about 2 minutes shorter to have them a little underdone.
Kristin
I never comment on food blogs ever but I had a hell of a time finding a recipe to trust and follow to make this type of cake. I only made the glaze part and it came out perfect. I used Ghirardelli white chocolate chips and omitted the cornsyrup. Everything else stayed the same. I also had two 8inch rounds and this amount of glaze covered it. My son loved his 5th birthday galaxy cake and I'm so grateful for this recipe!!
Dorin Even Hen
Beautiful cake! I will be making it for my boyfriend for his acceptance to the astrophysics faculty in the university 😀
Yoshi
How do I know which chocolate is "couverture"? Is there a specific brand? Thanks!
Sabine
If it is couverture, it stands on the package. You usually find it in the baking department as it is special chocolate for baking. But you can go with every high-quality white chocolate bar that is suitable for baking and tenderly melting. Do not melt chocolate chips because they don't melt so beautifully as it needs to be.
Dianna
What kind of gelatin? Does it matter?
Sabine
I use regular animal gelatin for this recipe. I didn't try this recipe with any vegan gelatine substitution yet.
Mary
I only used the mirror glaze portion of this recipe but it turned out great! I’ve been intimidated to try but this was simple with stunning results. Thank you!
Marie C.
Do I have to use Couverture or can I substitute with melting chocolate discs?
Sabine
I really suggest using couverture for the glaze because it's so crucial that the chocolate stays smooth when it cools down a bit. Some brands of regular baking chocolate start hardening and crumbling once they cool down. I hope that helps!
Brittany
Would you mind sharing where you purchased the silicone cake pop mold? I would like to purchase one.
Sabine
I bought it on Amazon. I hope that helps.