-
To make the cookies: Preheat the oven to 375°F with racks in the top and bottom thirds. Grease two baking sheets or line with parchment.
-
Working in a large bowl with a flexible rubber spatula, or using a stand mixer fitted with the flat beater or an electric hand mixer, mix the butter, oil, sugar, molasses, cake enhancer, baking powder, baking soda, salt, and spices until well-combined.
-
Scrape the bottom and sides of the bowl, then whisk in the eggs one at a time, until the mixture is fluffy. (If using a stand mixer, use the flat beater attachment throughout the whole process.)
-
Whisk in the pumpkin until well-combined.
-
Add the flour in two additions, stirring well with a flexible rubber spatula after each addition.
-
Use a 4 Tablespoon Scoop to deposit the thick batter onto the prepared baking sheets (about 67g each), leaving about 2" around each mound. You may not be able to use all of the batter.
-
Bake, rotating top to bottom and back to front halfway through, until the cookies are puffed and set; a slight indentation will remain when you gently press them in the middle, 14 to 16 minutes.
-
Remove from the oven, cool on the baking sheets for 5 minutes, then move to a rack to cool completely. Once the baking sheets are cool, portion and bake any remaining batter.
-
To make the filling: Using a stand mixer or an electric hand mixer, beat the cream cheese and butter until smooth and fluffy.
-
Beat in the confectioners' sugar in two additions.
-
Add the vanilla and xanthan gum. Increase the speed to medim-high and beat until pale and fluffy, 2 to 3 minutes.
-
Stir in the crystallized ginger.
-
To assemble the Pumpkin Whoopie Pies: Portion a scant 2 tablespoons (about 30g) of filling onto the flat side of half of the cookies (a 2 Tablespoon Scoop is a helpful tool here). Transfer the filled whoopie pies to the refrigerator, uncovered, for about 20 minutes, which will help the filling to firm up. For best storage, wrap each pie in plastic wrap.
-
Storage information: Store Pumpkin Whoopie Pies for several hours at room temperature; refrigerate leftovers, tightly wrapped, for up to 3 days. Whoopie pies are best served at room temperature, so let them sit at room temperature for 20 to 30 minutes before serving.