Will my bizcocho dominicano cake rise? I'm planning to make the cake batter from scratch on Sunday, refrigerate it (not freezing!) for about 3 days, and bake it up on Wednesday. But I'm cramped for time on that day.

I've researched that the cake wouldn't rise as high, and one of bizcocho dominicano's known qualities is to be light. This probably isn't relevant, but I'm turning the cake recipe into a cupcake recipe.

What if I make the batter and leave out the baking powder until Wednesday? Then I can put the powder in and mix the batter so it can become fluffy again. Do you think this'll work? Will it still rise?
Sorry, but no.

The baking powder aids in making the cake light, but the main "rising agent" is actually the air incorporated in the batter by patient whipping, together with the eggs. 

Now if you plan to store the batter for three days and then making up for the deflation by whipping again, you'll totally lose the fluffyness: The flour will have developed a lot of gluten during the storage time and the mixing after that time will aid in that again, resulting in a very dense cake.The rule for this kind of batter is always to mix and then bake as fast as possible.

If you can't reschedule to bake on Wednesday, you could probably bake the cake or cupcakes at a convenient earlier date, e.g. Sunday, and freeze them, then defrost either Tuesday night or Wednesday morning, decorate and serve.