Preheat the oven to 325°. Liberally butter and flour a 10" bundt pan. Set aside.
Toast the walnuts in the oven for 10-12 minutes or until fragrant and browned. Chop and set aside.
While nuts are baking, combine the whole wheat flour, all purpose flour, sugar, brown sugar, baking powder, baking soda, salt and apple pie spice in a large bowl. Whisk to combine.
Add the crystallized ginger, butter and eggs to the flour mixture and beat until crumbly. Add the buttermilk and beat on medium speed until the batter is smooth.
Stir in the apples, golden raisins and chopped walnuts and mix to combine.
Transfer the batter to the prepared bundt pan. Place the bundt pan on a sheet pan lined with parchment paper or foil (to catch any spills). Bake for 60- 70 minutes or until a cake tester comes out clean.
Cool on a baking rack until cake comes to room temperature. Transfer the cake to a serving platter.
FOR THE MAPLE GLAZE:
In a small saucepan, combine the butter and maple syrup. Heat over medium heat, stirring constantly until the butter has melted completely. Remove from heat and stir in the confectioners sugar and vanilla until smooth.
Pour the glaze immediately over the cake. It will start to firm up almost instantaneously.