This also happens to be pretty low fat since you use applesauce instead of oil 
Coffee Cake:
2/3 cup all-purpose flour
1/2 cup whole wheat flour
1 tsp baking soda
1 tsp ground cinnamon
1/4 tsp salt
2 small apples, finely chopped and peeled
1 egg
3/4 cup sugar
1/4 cup chopped walnuts
1/4 cup applesauce
Topping:
1/4 cup packed brown sugar
1 tbsp all-purpose flour
1 tbsp whole wheat flour
1/2 tsp ground cinnamon
1 tbsp earth balance or butter
1/4 cup chopped walnuts
Spray 9 inch round baking pan with nonstick cooking spray and set aside. In a small bowl stir together the flours, baking soda, cinnamon, and salt for the cake.
Combine apples and egg. Stir in the sugar, nuts, and applesauce. Add dry mixture. Stir and pour into prepared pan.
For the topping: Stir together the brown sugar, flours, and cinnamon. Cut in the butter. Stir in nuts. Sprinkle over batter in pan.
Bake in a 350 oven for 30 minutes or until a wooden toothpick inserted near the center comes out clean. Serve warm.
