Gently use a fork to press down and break up the jam to a point of being spreadable. It's inevitable that you will get a few crumbs in the jam, but you're going to be sprinkling crumble over it anyway. So, that's fine. Be sure that you are not removing any cookie molds (English muffin rings or cookie cutter) before the jam is spread. In the whoopie pie pan or with the English muffin rings it will be easier, since those have sides that aren't removed until after baking. But, if you're using the cookie cutter as a mold, spread the jam before taking the cookie cutter off. That will help stabilize the cookie dough while you are spreading the jam.