Preheat oven to 350°. Mix all donut ingredients together, scoop donut mixture into donut pan to make 6 donuts. Bake at 350° for 10 minutes. While the donuts are cooking, mix all icing ingredients together except for pumpkin pie spice. Once donuts are done, remove from oven and let cool for 5 minutes and remove donuts from pan. Top with icing and dust pumpkin pie spice on top of icing.