Preheat the oven to 350 degrees. Lightly spray a 9-inch round baking pan with cooking spray.

In a small bowl, mix the walnuts, sugar, and ¼ teaspoon cinnamon. Set aside.

In a medium mixing bowl, combine the milk, egg, and maple syrup. Stir in the grated apple.

In another large mixing bowl, sift together the flour, baking powder, baking soda, remaining cinnamon, salt, and nutmeg. Add flour mixture to apple mixture and stir gently just until combined.

Transfer the batter into prepared pan, spreading evenly. Sprinkle with the pecan mixture.

Bake for 30 minutes, or until toothpick inserted in center of cake comes out clean. Transfer the pan to a wire rack and cool slightly.