Heat oven to 375. Spray a 10" bundt pan w/ cooking spray. In bowl, combine flours, baking powder, baking soda and ginger. In lg bowl, beat butter for 30 seconds. Beat in sugar until combined.
Add egg, egg yolk and maple syrup. Beat 1 min. Alternately beat in flour mix and water to butter mix. Beat until combined. Pour batter into pan and bake for 45 min, or until a toothpick inserted in center comes out clean.
Cool cake and make frosting: In bowl, beat 1/2 cup powdered sugar and butter until combined. Beat in syrup then 1 cup powdered sugar. Add milk to make a drizzling consistancy. Drizzle over cooled cake.