Does anyone know how to make one base cake mix and then make several flavors for cupcakes? I was thinking a basic white cake mix then SPLITTING mix into Vanilla Bean, Chocolate and Strawberry. Thank you in advance.
Adjusting a basic cake (either from a boxed mix or from scratch) is easy if the cake has no or very little flavour of its own.
Using a boxed mix might be more difficult because they often have a generous amount of flavouring, typically vanilla, even if it does not explicitly say so on the box front. Check the ingredients list or use a mix you know - a little vanilla is ok.
You can either prepare the basic recipe, then divide the batter (I'll call this method 1 for now) or divide the ingredients and make separate batches (method 2). The latter might be difficult if you need to split eggs, but it's possible. See this question.
Now for the adjustments you asked for, amounts suggested should be enough for 1/3 to 1/2 of normal recipe:
Note that you can mix-and match the methods above, e.g. add one tbsp cocoa and 1 tsp of brandy or dissolve the vanilla bean scrapings in a bit of of whiskey. Chocolate goes nicely with a pinch of cinnamon, you could even go all "Christmasy" (ha, and to post this on Easter...) with gingerbread spice or brandy, cinnamon & nutmeg for "eggnogg".
To add to Stephie's great post:
Strawberry: Strawberry Nesquick Powder can be added to white/vanilla boxed cake mix and it will turn out okay. Just one of those "if you have it on hand, it can work" things. I still prefer just buying a box of strawberry cake though, the flavor comes through stronger.
Some recipes that use it:
My response is regarding the Chocolate addition of the three cake flavors. Just keep in mind when adding cocoa powder to a cake recipe (that is assuming it is a scratch recipe), you have to treat the cocoa powder like flour. Adding it to a recipe without subtracting the amount of flour equal to your cocoa powder will result in a dryer cake.
Ex. If you have a recipe that calls for 4 cups flour, you want to add 1/2 cup cocoa powder, you must remove 1/2 cup flour from the recipe. This will ensure your cake comes out as predicted...delicious!
Note When using a box mix of cake, I have not personally tried adding cocoa powder. Since all the leavening agents are already mixed into the bag, removing any of the mix of flour for equal amounts of cocoa can alter your cake possibly for the worst. My response is simply for making a from scratch cake recipe.