Here's a scratch chocolate cake that is really wonderful:

Chocolate Cake

3 cups flour
2 cups sugar
6 Tblsp cocoa
2 tsp baking soda
1 tsp salt
2 tsp vanilla
2 Tblsp vinegar
3/4 cup oil or melted shortening (can substitute unsweetened applesauce)
2 cups water

Mix all together. Pour into two 8 inch round pans or one 9x13 pan. Do not grease pans. Bake at 350 degrees F for 25-30 minutes or until center springs back when lightly depressed.