Preheat the oven to 350ºF. Line two 8-inch round cake pans with parchment paper and spray with non-stick baking spray. Sift together the flour, baking powder, baking soda, cinnamon, ginger, nutmeg, allspice, and pepper over a medium bowl; stir in the salt and set aside.

In the bowl of a stand mixer fitted with the paddle attachment, cream the butter and sugars until light and fluffy, about 5 minutes. Add the eggs one at a time, scraping down the sides of the bowl after each addition. Alternate adding the flour and buttermilk, beginning and ending with the flour. Add the pumpkin and beat until smooth. Divide the batter equally between the prepared pans. Rap the pans lightly on the counter to release any air bubbles. Bake for 30-40 minutes or until a toothpick inserted in the middle comes out clean. Place the pans on a wire cooling rack and allow the cakes to cool for 10 minutes. Invert the cakes onto the racks, remove the parchment, and cool completely.

To assemble the cake, place one cake on a serving platter. Frost the top of the cake and place the second layer on top. Frost the sides and top. Allow the frosting to set before serving, about 1-2 hours. Enjoy!