Super soft Fluffernutter Cupcakes with an intense peanut flavor. Double peanut butter in the game today - in the dough and stuffed into the cupcakes. Topped with an irresistible marshmallow frosting on top. Fluffernutter Heaven.
Preheat oven to 350°F (175°C). Line a 12-cup cupcake pan with cupcake liners and set aside.
Cupcakes: Mix flour, baking powder, and salt together in a small bowl and set aside. With a handheld or stand mixer fitted with a whisk attachment whisk butter, peanut butter, sugar, and vanilla* on medium speed for about 2-3 minutes until fluffy. Beat in egg until combined. Alternately mix in flour mixture and milk on low speed just until combined. Pour batter evenly into cupcake liners. Bake for about 23-25 minutes until golden brown and a toothpick centered in the middle comes out clean. Let cool completely.
Marshmallow Frosting: Beat butter with sugar until light and fluffy for about 2-3 minutes. Stir in marshmallow fluff by hand.
Fill cooled cupcakes with peanut butter. Therefore, use the back of a piping tip, place it in the middle of your cupcakes, and press down. Lift cut pieces with a sharp knife and remove them. Use your fingers to even the holes to a 3/4 inch deepness. Place 1/2 tablespoon of peanut butter into the holes. You can use more or less peanut butter depending on your taste. In this case, adjust the size of your holes. I don't replace the cupcake pieces, but you can do it if you want so. Pipe frosting with a piping bag on top of the cupcakes. Store in an airtight container at room temperature up to 3 days.
*First, cut off the straight end of the vanilla bean. Then place the tip of your sharp knife below the curled end and cut the vanilla bean through the middle of the bean lengthwise. Although you don't need to cut it all the way through, it's ok when you do so. Then open the vanilla bean and scrape out the flavorful seeds with the back of your knife. Just use the seeds.