This yellow cake from scratch recipe works great for birthday cakes.
Grease and flour 2 x 9-inch round cake pans and preheat oven to 350F.
In a large bowl, beat together butter, sugar, eggs, milk and vanilla.
Add flour and baking powder and blend until smooth.
Pour batter into the prepared pans, diving between pans evenly.
Bake for 30 minutes, or until toothpick inserted into the center of the cake comes out clean.
Allow cakes to cool fully before turning them out onto wire racks.
In large bowl, beat together butter, cocoa, sugar, milk and vanilla until smooth.
On large plate, place one of the cake and frost the top.
Place second cake on top and frost top and sides.
Decorate with funky birthday candles or sparklers (or however preferred :)