1/2cupMilk - 2% or whole milkwarmed in the microwave for 30 seconds
Gel food coloring in rainbow colorsred, orange, yellow, green, blue, purple
2cupsUnsalted Butterslightly melted
Rainbow Sprinklesoptional, for decoration
How To Make Cupcakes
In a large bowl, beat together the butter and the sugar until thoroughly combined, for about a minute.
Add in the eggs and vanilla extract and beat until smooth (about 1-2 minutes).
Next, beat in the sour cream and milk.
In a medium bowl, combine the flour, baking powder, baking soda, and salt.
Beat the dry ingredients into the wet ingredients until just mixed.
Preheat the oven to 350 degrees F.
Divide batter evenly into six small bowls
Use the gel food coloring to make six different colors of batter: red, orange, yellow, green, blue, and purple.
Line 18 muffin cups with paper cupcake liners.
To create a beautiful layered rainbow look, you’ll want to layer the batter by color in the muffin cups. Start with two teaspoons of purple batter in the bottom of all the paper muffin liners, which will help to distribute the batter between all 18 cups evenly.
Repeat the steps with the green, yellow, and orange batter in all muffin cups to create layers of colors. Finally, top with the red in each muffin cup. Each muffin liner should be about two-thirds full.
Bake your colorful cakes for 15-16 minutes, or until a toothpick inserted into the center of a cupcake comes out clean
How to Make Buttercream Frosting
Beat butter, confectioners' sugar, and vanilla on high in a large mixing bowl until nice and fluffy (about 5 minutes).
Pipe this on top of the cooled cupcakes using a piping bag.
It's best to fill each of the cupcake paper liners with a layer of color before moving on to the next color rather than focusing on layering one liner with every color one by one and then moving on. This ensures that you have enough colored batter for each cup before starting with the next color.