Unroll crescent rolls and place on a 12-inch round pizza pan. Press seams together and cover bottom and up the sides a little. Spread chili beans and their gravy over all evenly. Add the cooked ground beef and onion on top of the chili beans. Place the sliced tomatoes evenly over all to cover. Add the hot sauce, if desired. Sprinkle chili powder over all. Top with mozzarella cheese. Bake at 350 degrees F for 25 minutes or until browned on edges. Remove from oven and let set for five minutes before cutting and serving.