Place mushroom, with the opening facing up, in a single layer in a 13x9 baking dish.
Add ¾ cup parmesan cheese, ¾ cup of panko crumbs, and remaining ingredients to a mixing bowl. Stir to thoroughly combine. Fill each mushroom cap with the crab mixture (should be over stuffed a bit). Sprinkle with remaining parmesan cheese and panko crumbs. Bake for 20 minutes.