Preheat oven to 340 F. Grease and line pans with parchment paper.

In a separate bowl, cream butter and add in sour cream, milk, vanilla, and eggs.

Add butter mixture into the flour mixture and mix until just combined.

Pour batter into pans, making sure to only fill halfway.

Bake for 25-30 minutes or until toothpick inserted comes out clean. Cool 5-10 minutes in the pan before transferring to wire racks.

Beat butter until light and add in vanilla.

Gradually beat in powdered sugar, adding in the milk.

Beat until fluffy and stir in the sprinkles.

Once cakes have cooled completely, trim tops so they are even and flat.

Using the 3-inch cutter, cut 4 circles out of the 9-inch cake.

Place one 6-inch cake onto a piece of parchment paper on top of a cutting board or plate. Frost the top of the cake and then place the second 6-inch cake on top of it. Frost both of these cakes, making sure the edges are smooth.

Place two of the 3-inch cakes at the top to make Mickey’s ears. Frost the tops, and place a second 3-inch cake on top of each ear. Frost both cakes completely. If the ears are not level with the head, either trim the cakes before frosting or add a bit of frosting to make up the difference.

Add candles and a birthday message if desired.