Recipe from Tasty Kitchen
1 cup cake flour
1 1/2 tsp baking powder
1/2 cups all purpose flour
1 cup sugar
1/4 tsp salt
1/2 cup unsalted butter (room temperature, cut into pieces)
2 eggs (room temperature)
1/2 cups milk
2 tsp vanilla extract
red, orange, yellow, green, blue, purple food coloring
1 1/2 stick unsalted butter (room temperature)
2 cups powdered sugar (sifted)
1 1/2 tsp vanilla extract
blue food coloring
rainbow sour strip candy (garnish)
How to make them:
Preheat oven to 350˚F.
Line a 12 count muffin pan with cupcake liners.
Using an electric mixer with a paddle attachment, pour the dry ingredients (flour through salt on the above list) into a bowl and mix for 2-3 minutes, until well combined.
Add the cubed softened butter, mix on low speed until butter is well-coated and pieces are small and crumb-like, about 20-30 seconds.
Add eggs, one at a time, until combined. (Make sure egg yolk is completely mixed in before adding second)
Slowly add the milk and vanilla, scrape down the sides are you go.
At this point you can dye the batter.
Evenly pour the batter divided by 6 bowls.
Put a drop or two of food coloring in each bowl, so that you have 1 bowl of batter red, 1 orange, 1 yellow, 1 green, 1 blue, and 1 purple.
Next, fill the cupcake liner with a spoonful of purple batter, then blue, green, yellow, orange, and red should be on the top, about 2/3 full.
Bake for 17-20 minutes or until tops are slightly golden brown and toothpick inserted into the center of the cupcakes come out clean.
Take cupcakes out of the muffin pan and transfer to a cooling rack.
Cool before frosting.
In a bowl of an electric mixer, beat butter on medium-high speed until pale and creamy, about 2 minutes.
Reduce speed to medium.
Add sugar, 1/2 cup at a time, beating for 2 minutes after each addition.
Add vanilla and beat until buttercream is smooth.
Add a drop or two of blue food coloring, mix until well incorporated.
Spread or pipe onto cooled cupcakes.
Decorate with a rainbow sour strip then ENJOY!