I love these cupcakes.  There is something so yummy about the fluffy light cake and the classic buttercream frosting.  Filled with your favorite sprinkles, they are ready to help you celebrate your favorite people.  

Confetti Cupcakes with Buttercream Frosting
(Makes 24 cupcakes)

1 cup milk
5 egg whites
2 t vanilla extract (I used Mexican vanilla)
3 cups cake flour
1 ½ cups granulated sugar
4 t baking powder
½ t kosher salt
¾ cup (1 ½ sticks) unsalted butter, cut into 1-inch chucks, at room temperature
½ cup of favorite sprinkles (I used these from Williams Sonoma)

Preheat the oven to 350 degrees. Position a rack in the middle of the oven. 
Line 24 cupcakes cups with paper liners.

In a small bowl, whisk together ¼ cup of the milk, the egg whites, and vanilla. Set aside.

Using a mixer, mix flour, sugar, baking powder, and salt on low speed until thoroughly combined.  With the mixer on low speed, add the butter, mixing until the mixture resembles coarse sand.  Gradually add the remaining ¾ cup milk and beat for 1 or 2 minutes.  Using a rubber spatula, scrape down the sides of the bowl.

With the mixer on medium speed, gradually add the egg mixture.  Mixing well and scraping down the bowl as necessary.  Gently fold in the sprinkles.

With a large ice cream scoop or spoon, scoop the batter into the prepared cupcake liners, filling them about two-thirds full.  

Bake for 20 to 25 minutes, until a cake tester inserted in the center of a cupcake comes out clean.  Let cool for 15 minutes, then remove the pans and cool completely on a wire rack.

Cool completely before frosting the cupcakes.  

Buttercream Frosting

1 cup (2 sticks) unsalted butter, cut into 1-inch chucks, at room temperature
6 to 7 cups powdered sugar
½ cup milk
2 t vanilla extract (I used Mexican Vanilla)
A few drops of liquid gel food coloring (optional)

In a mixer, cream the butter on medium for 2 or 3 minutes, until light and fluffy.  Add 4 cups of the powdered sugar, ¼ cup of milk, and the vanilla and mix on low speed, until smooth and creamy.  Add the remaining ¼ cup of milk and mix until incorporated, 1 to 2 minutes.  Gradually add 2 cups more sugar, then add up to 1 cup more sugar if the frosting seems thin, and beat on low speed for 3 to 5 minutes, until the frosting is light and fluffy.

If you want to tint the frosting: Add a drop or two of food coloring to the frosting, mixing well, then add more coloring as necessary until you reach the desired shade. If you want multiple colors, scoop frosting into several bowls, then add food coloring. 

The frosting can be used immediately or stored in an airtight container at room temperature for up to 2 days or refrigerated for up to 1 week.  If you refrigerate, bring to room temperature before you use it.  Then transfer the buttercream to a mixer.  Beat on medium-high until light and fluffy, 2 to 3 minutes.