Learn how to make a Rainbow Cake from scratch. With super easy frosting technique no complicated piping and spreading needed. Rainbow colors inside and around the cake. No boring white frosting! Soft almond meringue rainbow cake layers frosted with creamy marshmallow buttercream rainbow frosting and decorated with fluffy meringue frosting. The most beautiful and delicious Rainbow Cake ever.
Colorful Rainbow Cake Recipe
Spring is here, guys!
The sun is shining, the days are getting longer, the flowers start to bloom, and the energy level rises again. Woohoo. Let's celebrate the beginning of spring with a beautiful and colorful Rainbow Cake.
This Rainbow Cake recipe is not just the most beautiful one, it is the most delicious one too. Almond meringue cake layers frosted with a marshmallow buttercream frosting....yap, it is as delicious as it sounds.
Rainbow Cake might look intimidating at first glance, but it is not as hard to make as it looks like. Watch the 1-minute-video to see how to make a Rainbow Cake from scratch.
If you already mastered my Mirror Glaze Galaxy Cake recipe, then this Rainbow Cake recipe is a walk in the park for you.
How to make a Rainbow Cake
The process of this Rainbow Cake Recipe is clear and well structured. We don't have many ingredients what makes the process much easier and faster.
In fact, you need just egg whites, sugar, salt, flour, almond flour (finely ground blanched almonds without skin) for the almond meringue cake layers. And colors of course.
The marshmallow buttercream contains just butter, powdered sugar, marshmallow cream, and salt. Yes and again colors of course.
This means that you need just 5 ingredients for the rainbow cake layers and 4 ingredients for the rainbow frosting + colors.
Speaking of colors. You need
- indigo blue
for this Rainbow Cake recipe.
Rainbow Cake Layers
To make the Rainbow Cake layers mix egg whites and salt until soft peaks form. Add sugar and mix until glossy and stiff. At least 5 minutes. The meringue needs to have a solid stand.
Then separate into 7 bowls equally and color with violet, indigo blue, blue, green, yellow, orange, and red. Take as much coloring as desired. Mix just until evenly colored. Then fold in almond flour and flour.
The more color you use, the more intense and darker the layers are. Less coloring leads to a pastel tone. Read the instruction on the package if you are not sure how much to use. I recommend using gel or paste coloring.
Draw seven 8" circles on parchment paper and flip over the paper. Spread meringue into the drawn circles till the outer edges.
Don't bake the meringue too long to prevent them from browning too much. Too much browning affects the color of your cake. Remove from oven when dry to touch. After baking immediately remove the baking paper and let cool to room temperature.
Well, one part of the Rainbow Cake is done! Awesome!
To have not just a beautiful Rainbow Cake but also a delicious one, I've decided to combine the almond meringue cake layers with a delicious marshmallow buttercream frosting.
After mixing the butter, powdered sugar, marshmallow cream, and salt separate the frosting into 8 bowls. Color again with violet, indigo blue, blue, green, yellow, orange, and red.
Color the 8th bowl with blue to finish the cake on top with sky blue. Maybe you need to add a bit of white coloring to brighten up the color.
If you don't want to have a blue frosting on top, then separate the frosting just into 7 bowls and color with the rainbow colors.
When you color the frosting, place the cake layers next to your bowl and add the coloring little by little to reach the same tone of your cake layers. If your frosting is accidentally more colorful or darker as the cake layer, add a bit of white coloring to brighten up the color again.
The following frosting technique is a simple way to get the rainbow stripes around the cake without piping and spreading the frosting.
Place a closed 9" springform ring on a cake plate or stand. Place the violet meringue cake layer in the middle of the ring. Spread a bit of frosting underneath that the cake layer doesn't move around while frosting. Remember, the cake layers have a size of 8".
Then spread the violet frosting on top of the cake layer and till the edges of the springform ring that the bottom is evenly covered. Watch out that you don't color the inside of the ring higher than the violet layer ends if you want to have straight lines on the sides. The accuracy of your work affects the shape of the lines on the sides of your Rainbow Cake.
I didn't work that accurate because I love how the colors blur into each other. But it's up to your preference.
Then chill at least 4 hours or overnight before removing the ring.
After chilling remove the ring. For the best results, run an icing spatula around the sides before removing. This makes sure that no frosting sticks to the ring while removing. Press the spatula outwards against the ring while running around the sides.
If necessary, level the sides of the cake with the spatula. Do this by planting the spatula on one side of the cake uprightly and spin around the cake. Do this without pushing too much against the cake.
I decorated my Rainbow Cake with super fluffy meringue to get the most beautiful cloud shape on top. If you don't want to decorate your Rainbow Cake with meringue, replace it with whipped cream, or marshmallows, and sprinkles.
To make this super fluffy and cloud-like meringue, combine egg whites, sugar, and water in a heat-proof bowl. Then place the bowl over simmering water and mix until stiff peaks form. This will take about 10 minutes. Then remove from heat and mix additional 5 minutes until cooled.
Pipe meringue in back and forth movements on top of the cake to create an irregular shape of a cloud.
This is the best RAINBOW Cake Recipe in the world because
- it has rainbow colors inside and around the cake
- there is no boring white frosting covering the Rainbow Cake
- soft almond meringue cake layers meet creamy marshmallow buttercream frosting
- you don't need to complicatedly pipe and spread the frosting on and around the cake
- it's a beauty
- it is unbelievably delicious
- you can make it for special occasions like Birthday's or just for fun (PERFECT BIRTHDAY CAKE!!)
- this is the cutest cake ever
Happy RAINBOW Cake baking!
If you make this colorful Rainbow Cake Recipe, leave a comment, rate it and tag a photo #alsothecrumbsplease on Instagram! Would love to see your snap!
You may also like Mirror Glaze Galaxy Cake Recipe, White Cake with Strawberry Frosting for Valentine's Day, The Best Homemade Croissant Recipe, Hungarian Esterházy Torte Recipe, or click here to see all things sweet.
Rainbow Cake Recipe
- 12 large egg whites
- 1/4 tsp salt
- 1 1/2 cups caster sugar (300g)
- 28 tbsp almond flour (224g)
- 7 tbsp flour (63g)
- gel or paste food coloring: violet, indigo blue, blue, green, yellow, orange, red
- 2 cups butter (452g)
- 5 cups powdered sugar, sifted (600g)
- 7 oz marshmallow cream (200g)
- 1/4 tsp salt
- gel or paste food coloring: violet, indigo blue, blue, green, yellow, orange, red
OPTIONAL: Meringue for decoration (or replace with whipping cream, marshmallows, or sprinkles)
- 4 large egg whites
- 2 cups caster sugar (400g)
- 1/4 cup cold water (60ml)
- Preheat oven to 320°F (160°C).
- With a pencil, draw seven 8“ (20,3cm) circles on parchment paper. Then flip over the parchment paper and place on baking sheets.
- In a large mixing bowl with a handheld or stand mixer fitted with a whisk attachment, whisk egg whites and salt on medium-high speed until soft peaks form. Add sugar and whisk until glossy and stiff peaks form. Separate into 7 bowls equally. Color with violet, indigo blue, blue, green, yellow, orange, and red. Use as much gel or paste food coloring to your preference. Stir on medium-high speed just until combined and evenly colored.
- With a wooden spoon fold into each color 4 tbsp of almond flour and 1 tbsp of flour carefully. Equally spread the meringue into the drawn circles till the outer lines. Make sure that they are almost the same in size and thickness. Bake one layer at the time for 17-20 minutes until dry and not too browned (very lightly browned is ok). Remove from the oven when dry to touch. Immediately flip over the parchment paper and remove the paper. Let cool to room temperature.
- Mix butter with a handheld or stand mixer fitted with a whisk attachment on medium-high speed until creamy for about 2 minutes. Add about 1 + 1/2 - 2 cups sugar at the time and mix on low speed until combined. Add marshmallow cream and salt and mix to combine. Separate the buttercream into 8 bowls. Color with violet, indigo blue, blue, green, yellow, orange, and red in the same tone as your meringue layers are. Add white coloring to lighten up the colors if needed. Color the 8th bowl with blue and white to create a sky blue tone for the top of the cake.
Assemble the cake
- Place a closed 9" springform ring on a cake board or cake stand. Place the violet meringue cake layer in the middle of the ring. Spread a bit of frosting underneath the cake layer that it doesn't move around while frosting. Then spread the violet frosting on top of the cake layer and till the edges of the springform ring that the bottom is evenly covered. Watch out that you don't color the inside of the ring higher than the violet layer ends if you want to have straight lines on the sides. The accuracy of your work affects the shape of the lines on the sides of your Rainbow Cake. Repeat with indigo blue, blue, green, yellow, orange, and finish with red on top. Spread remaining sky blue on top evenly. Chill for 4 hours or overnight.
- OPTIONAL: Make the meringue: Fill a large saucepan 1/2 full with water and bring to a simmer over medium-low heat. In a heatproof bowl, whisk together egg whites, sugar, and water to combine. Place bowl oblique over the saucepan that the hot steam can escape around the sides of the mixing bowl. The bowl should not touch the simmering water. With a handheld mixer fitted with a whisk attachment, beat egg white mixture for 10 minutes or until shiny, glossy, and stiff peaks form. Make sure the meringue doesn't get too hot, or the egg whites will cook through, and the meringue will be lumpy. Remove from saucepan in-between to cool down a bit, if necessary. Not just that the meringue is lumpy in structure when cooked too hot, it also will smell and taste like cooked eggs whites instead like a meringue. Remove from heat and mix until cooled for about 5 minutes.
- Remove cake from the fridge. Run an icing spatula around the sides (push outwards against the ring while moving), open the springform ring and remove it. If necessary, level buttercream on the sides with the spatula by placing it on one side of the cake uprightly and spin around the cake without pushing too much against the cake. Pipe meringue with a piping bag fitted with a round tip on top of the cake. Go back and forth with the tip while piping to create an irregular cloud shape. Alternative decorate the Rainbow Cake with whipping cream, marshmallows, or sprinkles on top instead of meringue if preferred. Store leftovers up to 3 days in the fridge.