Yes. Prepare the filling and batter in separate mixing bowls, cover with plastic wrap, and refrigerate for 1-2 days. When you want to bake it, bring the two mixtures back to room temperature while you melt the butter in the pre-heating oven, then continue with the recipe as written. It can also help to leave the baking powder out of the batter mixture until just before pouring it over the blueberry filling.