Ingredients
Scale
- 1 ½ cups all-purpose flour
- 1 cup granulated sugar
- 1 ½ teaspoons baking powder
- ½ teaspoon salt
- ½ cup unsalted butter, softened to room temperature
- 1 large egg, room temperature
- ½ cup full-fat sour cream
- ½ cup whole milk, room temperature
- 2 teaspoons pure vanilla extract
- ½ cup rainbow sprinkles (jimmies work best)
- 1 cup unsalted butter, softened
- 3 cups powdered sugar, sifted
- 2 tablespoons heavy cream
- 1 teaspoon pure vanilla extract
- Extra rainbow sprinkles for garnish
Instructions
- Preheat your oven to 350°F (175°C). Line a standard 12-count muffin tin with paper liners. In a medium bowl, whisk together the all-purpose flour, baking powder, and salt. Set the dry ingredients aside.
- In a large mixing bowl or the bowl of a stand mixer, beat the softened butter and granulated sugar together on medium-high speed. Continue beating for about 2 to 3 minutes until the mixture appears light and fluffy. Scrape down the sides of the bowl as needed.
- Add the egg, sour cream, and vanilla extract to the butter mixture. Beat on medium speed until fully combined. Lower the mixer speed and gradually add half of the dry ingredients, followed by the milk, and then the remaining dry ingredients. Mix until just combined; do not overmix.
- Gently fold in the ½ cup of rainbow sprinkles using a rubber spatula. This prevents the colors from bleeding into the batter. Distribute the batter evenly among the 12 cupcake liners, filling each about two-thirds full.
- Bake the cupcakes for 18 to 22 minutes, or until a toothpick inserted into the center comes out clean. Remove the tin from the oven and let the cupcakes cool for 5 minutes before transferring them to a wire rack to cool completely. They must be entirely cool before frosting.
- To make the frosting, beat the softened butter for 2 minutes until smooth. Gradually add the powdered sugar, heavy cream, and vanilla. Beat on high speed for 3 minutes until light and airy. Pipe the frosting onto the cooled cupcakes and immediately top with extra rainbow sprinkles.
- Cook Time: 40 minutes