I like to use this 'doctored' cake mix recipe for a very moist cake.

Black Forest Cake

1 chocolate cake mix (or Devil's Food, chocolate fudge, etc.)
1 1/4 cup water
1/3 cup vegetable oil
4 eggs
1 small box instant chocolate pudding

Blend all together and pour into two 8-inch round pans. Bake at 350° for 25-30 minutes or until a toothpick inserted into the middle comes out clean.
Cool completely and frost each layer generously with cream cheese frosting. Just before serving, spread a can of cherry pie filling over top.

You can cheat simplify and use canned frosting, or try this one:

Cream Cheese Frosting

1 box powdered sugar
1 stick butter
1 block cream cheese

Blend all together until smooth.