You do not have to use cocoa powder, however it is by far my favorite flavor ;). You may also throw in a handful of berries or other fruit, a tsp of vanilla extract, flavored jam or jelly, nuts, marshmallow cream (don't use regular marshmallows!), coconut, or whatever flavor you like. Try not to use watery fruit like watermelon or cantaloupe as they will make the ice cream runny. If you use smaller sized bananas, use three or four for one serving.