Preheat the oven to 350°F. Grease and flour two 9-inch round cake pans.

In a large mixing bowl, beat the softened butter, sugar, and vanilla until light and fluffy.

Add the eggs one at a time, beating well after each addition.

Alternately add the self-rising flour and milk, mixing just until fully combined and smooth.

Divide the batter evenly between the prepared pans.

Bake for 30–35 minutes, or until a toothpick inserted into the center comes out clean.

Let the cakes cool completely before frosting.

For the frosting, beat the softened butter in a large mixing bowl until creamy.

Gradually add the powdered sugar, about 1 cup at a time, mixing on low speed until incorporated.

Mix in the vanilla.

Gradually add the milk while beating on medium-high speed until the frosting reaches your desired consistency.

Use a serrated knife to trim the rounded tops of the cooled cakes so the layers are level.

Place one cake layer on a serving plate or cake stand and spread frosting over the top.

Place the second cake layer on top and frost the top and sides, reserving some frosting for decorating if desired.

Pipe the remaining frosting on top and add sprinkles, if desired. Slice and serve.