Heat oven to 350°F. In a bowl, combine the flour, baking powder, ginger, and salt. Set aside. Peel, core, and grate the apple. Set aside.
In a medium bowl, cream the butter with a mixer until smooth. Add the maple syrup in a slow stream and continue beating about 2 minutes. Add the eggs, 1 at a time, and increase speed to medium-high. Beat until the batter is smooth and fluffy, about 5 minutes.
Reduce speed to low and gradually beat in the flour mixture, then the milk, until smooth. Stir in the grated apple and walnuts, then pour into a greased 10-inch cake pan. Bake until lightly golden and a skewer inserted comes out clean, 40 to 45 minutes. Cool 10 minutes before removing from the pan. Garnish the cake with the apple chips.
Delicious!!! I cut the recipe in half and made nine reasonably-sized cupcakes. After reading the prior review, I got the idea to slice an apple into rings and put one ring in the center of the cupcake before baking. Baked 25 min and came out perfect. Husband says we are definitely making this again!