Butter a 6-cup muffin tin. Chop an apple into thin slices, put 3 slices in each cup. Mix 6 tablespoons oats, 3 tablespoons brown sugar and 1/4 cup melted butter in a small bowl. Put 1 tablespoon oat mixture on top of apples. Bake at 400F for 15 minutes. Enjoy!! Makes 6 muffin-cup sized portions.