Confetti Layer Cake

Ingredients

• ¾ cup rainbow sprinkles
• 6 large egg whites, room temperature
• 2/3 cup whole milk, room temperature
• 2 teaspoons vanilla extract
• 3 cups cake flour
• 1 ½ cups sugar
• 4 teaspoons baking powder
• 1 teaspoon salt
• 16 tablespoons unsalted butter, cut into 16 pieces and softened
• 4-6 drops yellow food coloring
• 1 pound (4 sticks) unsalted butter, cut into 32 pieces and softened (for frosting)
• ¼ cup heavy cream
• 1 tablespoon vanilla extract (for frosting)
• ½ teaspoon salt (for frosting)
• 4 cups (1 pound) confectioners’ sugar

Directions

1. For the frosting: mix butter, cream, vanilla, salt and confectioners’ sugar in a mixer until light and fluffy. (Makes about 5 cups.)
2. Adjust oven rack to middle position and heat to 350 degrees. Grease 3 8-inch round cake pans, line with parchment, and flour pans.
3. Pulse ½ cup sprinkles in a food processor until coarsely ground, 8-10 pulses; set aside.
4. Whisk together egg whites, milk and vanilla.
5. With the mixer, mix flour, sugar, baking powder and salt on low speed. With mixer running, add butter 1 piece at a time until mixture resembles moist crumbs.
6. Add all but ½ cup of the egg mixture and mix until just combined. Increase speed to medium-high and beat until light and fluffy, about 1 minute. Add remaining ½ cup egg mixture in a slow stream. Scrape down bowl and beat on medium-high speed until well combined, about 15 seconds. Stir in the ground sprinkles.
7. Divide batter evenly among prepared pans and smooth tops with a rubber spatula. Bake until a toothpick inserted in the center comes out clean, 21-25 minutes.
8. Let cakes cool in pans on a wire rack for 10 minutes. Remove cakes from pans, discarding parchment, and let cool completely on the rack, about 2 hours.
9. To assemble: mix food coloring into frosting. Place 1 cake layer on a plate. Spread ¾ cup frosting evenly over top. Top with second cake layer, then spread ¾ cup frosting evenly over top. Top with the 3rd cake layer. Spread remaining frosting evenly over top and sides. Press remaining ¼ cup sprinkles around the bottom edge of the cake and serve.