Step 1

Preheat oven to 350°F. Line the bottom of three 8-inch round cake pans with a piece of parchment paper cut to fit. Lightly grease and flour both cake pans and set aside.

Step 2

In a medium bowl, whisk together the flour, baking powder and salt. Set aside.

Step 3

In the bowl of an electric mixer fitted with the paddle attachment, beat the butter and sugar until very white and fluffy, about 4 minutes. Beat in the eggs, one at a time, making sure each one is well incorporated before adding another. Mix in the vanilla.

Step 4

With the mixer on low speed, alternate adding the flour mixture and the milk, ending with the flour mixture, until batter is smooth. Fold in 1 cup rainbow sprinkles with a spatula.

Step 5

Divide batter evenly among prepared cake pans. Bake cakes for 25-30 minutes or until a toothpick inserted in the center of each cake comes out clean. Let cakes cool in pans for 15 minutes before running a sharp knife around the edges turning out onto wire racks to cool completely.

Step 6

To make the frosting, beat the butter and cream cheese together in the bowl of an electric mixer fitted with the whisk attachment. Add the salt and vanilla. Beat in the powdered sugar, 1 cup at a time, until well combined. Add 1 tablespoon milk and beat on medium-high speed until frosting is fluffy and of spreading consistency. Add additional milk if the frosting is too thick or additional powdered sugar if the frosting is too thin to spread.

Step 7

Once cakes are cooled, use a sharp knife to trim around the edges so the inside of the cake is slightly exposed.

Step 8

Spread a small amount of frosting on the bottom of a cake stand or cake plate. Place one cake layer, top side down, on the cake stand. Spread a third of the frosting over the first cake layer, spreading it all the way to the edges. Repeat with remaining cakes and frosting. Cover the top layer of frosting with 1/3 cup rainbow sprinkles, gently pressing them into the frosting.

Step 9

Serve, eat and enjoy!