In a large mixing bowl, cream together the butter and sugars until fluffy. Beat in the pumpkin, buttermilk, eggs, molasses, and orange zest.
In a separate bowl, combine flour, baking soda, baking powder, pumpkin pie spice, and salt. Slowly add to the pumpkin mixture just until blended.
Fill paper-lined or greased muffin tin 2/3 full.
STREUSEL TOPPING DIRECTIONS
In a bowl, combine the flour and sugar. Add the cold butter and cut it in until the mixture is crumbly. Sprinkle the mixture over the tops of the muffins.
Bake in a 375 degree oven for 20 to 25 minutes or until a toothpick comes out clean. Remove from the oven and cool for about 5 minutes, then remove them from the pan and cool on a wire rack.
Hollis, Lee. The Death of a Pumpkin Carver. Kensington Publishing, New York, 2018.