The pumpkin puree lends a lightness to the texture and gives it enough moisture to stave off the dryness that tends to plague traditional black-and-whites.
I find buttermilk powder to be a very useful pantry staple and good substitute for buttermilk in baking. If you’d prefer to use fresh buttermilk you can substitute 3/4 buttermilk for the water and buttermilk powder used here.
I used Trader Joe’s pumpkin pie spice here, which includes cardamon and lemon peel in addition to the traditional cinnamon, ginger, and cloves.
The frosting recipe was adapted from Smitten Kitchen.