I'm making chocolate cupcakes for next Wednesaday in honor of National Chocolate Cupcake day. To save money, I'm using a box cake. I have white, yellow/butter, banana, and spice...no chocolate. How much cocoa powder do I need to add to get a chocolate cake? Or do I just add a little, taste to see if it's chocolaty enough, and keep adding more until I'm satisfied?

I'd say at least 1/2 cup of cocoa pwdr.