In bowl mix together dry ingredients. It's helpful to use a wire whisk; important with chocolate cake not so much for other flavors.
In mixer bowl place next 4 ingredients. Add about 1/2 of the dry ingredients and blend together, then add the rest of the dry ingredients and blend. Mix for 2 minutes.
Pour into prepared pans and bake as usual.
Any cake flavor can be used.
Match the flavoring to the cake flavor, such as use lemon/almond flavoring for lemon cake; strawberry for a strawberry cake etc, etc. For most flavors, you can use a mixture of vanilla, butter, and almond which is what I do most of the time.
You can use milk, juice, thawed frozen concentrates, soda pop (ie: Coke) or just about anything wet for the liquid.
This recipe is based on mixing in a kitchenaid mixer. I use position #1 to stir it, then #4 to mix the batter.
This makes the amount of batter as if you used 1 1/2 mixes and is perfect for a 10' square or 9x13 or one 8' and two 6' round; or two 8's round or a 12' round; and other combinations of pans.
I prefer to bake at 300 degrees for about 20 to 30 minutes (depending on size of cake) then turn oven up to 325 for about an equal time. If cake has pulled away from sides it is overbaked. After cooling, the top might be a bit sticky.
I have used plain or flavored yogurt instead of sour cream. I've always used all purpose flour.
You can be as creative as you want to be as long as you keep the measurements the same. Enjoy