Separate biscuits into 10 individual circles. Pat each biscuit into a 5" circle on a lightly floured board or surface. Press into muffin pans. Brown ground beef in a large skillet stir in ketchup, brown sugar, vinegar and chili powder. Spoon into muffin cups. Bake at 375 degrees for 15 minutes. Sprinkle with cheese and bake 5 minutes more.