Preheat oven to 350F and grease a 6" bundt pan or 12 mini bundt pans.
In a medium bowl sift together the flour, baking powder, salt and spices. Set aside.
Mix the sour cream, eggs, and egg yolk, set aside.
In a bowl of a standing mixer beat the butter and sugar until light and fluffy, about 3-4 minutes. Scrape the sides and bottom of the bowl.
Add the grated ginger and orange zest to the butter mixture and beat until combined.
Add the flour mixture, alternating with the sour cream mixture in three additions starting and ending with the flour mixture.
Scoop the batter into the greased pan(s) (if using mini pans, make sure not to fill it over 3/4) and bake for 40-45 minutes or until a toothpick comes out clean from the center of the cake.
Remove the cake from the oven and let it cool while you make the soak.