1. TOPPING: Combine all ingredients. Mix well.
2. MUFFINS: Combine flour, brown sugar, and baking soda in a large bowl.
3. Combine egg, yogurt and oil in a small bowl. Add to dry ingredients, stirring just until moistened. Stir in apples and cranberries.
4. Spray muffin pans, cups and tops with a nonstick spray. Fill muffin cups with batter. Sprinkle wirh topping.
5. Bake at 375F for about 25 minutes or until tops are firm to touch.