Preheat oven to 350 degrees F. Grease and flour a 12-cup Bundt pan.
Add the flour, baking powder, salt, and pumpkin pie spice to the bowl of a food processor. Pulse the dry ingredients for 10 seconds. Add the shortening and pulse until small crumbs form. (Think pie crust. If you don't have a food processor, combine the dry ingredients in a mixing bowl, and cut in the shortening using a fork.)
Transfer the flour mixture to a large mixing bowl, add the sugar, brown sugar, pumpkin puree, butter, eggs, and milk. Beat everything together on medium-low speed until just combined, scraping the bowl as needed. Pour batter into prepared pan.
Bake for 50 minutes or until a toothpick inserted in the center of the bread comes out clean.
Carefully remove the pan from the oven, and let cool for 10 minutes in the pan. Remove from the pan, and cool completely on a wire rack. (see note)
Notes
You can make this pumpkin bread with Bisquick to cut down on the prep if preferred. To do this, omit the flour, baking powder, salt, and shortening and use 3 cups of Bisquick instead. We made this bread with Bisquick growing up and it works both ways.
Sweeten up your bread with a simple glaze by whisking together 1 cup of powdered sugar, 1 tablespoon of milk, and 1/2 teaspoon of vanilla in a medium mixing bowl. Then pour the glaze over the cooled bread, letting it run down the sides.