Preheat oven to 350˚F.
Place flour, baking powder, cinnamon, ginger, baking soda, salt, and nutmeg in a mixing bowl and whisk together.
Place butter and both sugars in the bowl of a stand mixer, fitted with a paddle attachment, and mix together until light and fluffy.
Add eggs to the sugar and butter mixture, 1 at a time, scraping down the sides of each bowl after each addition, and beat together until well combined.
Pour the flour mixture into the wet mixture and beat together until just combined. Stir in the pumpkin puree and mix until fully combined and no lumps remain.
Pour the batter into a lightly greased, 9 inch bundt pan and bake for 55 to 65 minutes or until the top is golden brown and a toothpick comes out clean when inserted into the center of the cake.
Allow the cake to cool for 15 minutes before inverting onto a cooling rack. Then allow cake to finish cooling, about 2 hours.
While the cake cools, make the glaze: Place the milk and chopped pistachios in a small saucepan and simmer over medium-low heat. Simmer mixture for 10 minutes, remove from heat and cover. Allow the mixture to steep for 1 hour. Strain nuts from milk and discard.
Stir powdered sugar into the milk, ¼ cup at a time, until all the sugar has been added and mixture is smooth.
Pour glaze over the cooled cake and finish a sprinkle of chopped pistachios. Slice and serve.