Arrange an oven rack in the middle position and preheat your oven to 350° F (175° C). Line two baking sheets with parchment paper or silicone baking mats to prevent the cookies from sticking.

In a large bowl, whisk together the flour, salt, baking soda, baking powder, and pumpkin pie spice until all ingredients are well combined and evenly distributed.

In a separate large bowl, thoroughly whisk together the white sugar, packed dark brown sugar, and vegetable oil until smooth. Add the chilled pumpkin puree, and whisk to combine completely. Then add the eggs and vanilla extract, whisking until the mixture is homogeneous.

Sprinkle the flour mixture (from Step 2) over the pumpkin mixture (from Step 3). Whisk the mixtures together just until no streaks of flour remain and the batter is smooth. Be careful not to overmix, which can make the cookies tough.

Using a cookie scoop with a 1.5-2 tablespoon capacity, drop rounds of dough onto the prepared baking sheets, spacing them about 1 inch apart. Bake one cookie sheet at a time for 10-12 minutes, or until a toothpick inserted into the center of a cookie comes out clean. Remove from the oven and let the cookies cool on the pan for about 10 minutes. Transfer them to wire racks to cool completely. Repeat with remaining dough if needed. I like to give the cookies plenty of space so they form nice round shapes and don't stick together.

In the bowl of a stand mixer fitted with the paddle attachment, beat the unsalted butter on medium-high speed until smooth and creamy with no visible lumps. Add the softened cream cheese and continue beating until well combined. Gradually add the powdered sugar, then add the maple syrup and vanilla extract. Beat until the filling is smooth, but be careful not to overbeat it, or it may become too thin. If the filling seems too loose, place it in the fridge for about 30 minutes to firm up. For an extra depth of flavor, I like to use pure maple syrup.

Turn half of the cooled cookies upside down. Pipe or spread a generous amount of the prepared maple cream cheese filling onto the flat side of each overturned cookie. Place a second cookie, flat side down, on top of the filling to form a sandwich, gently pressing until the filling extends to the edges. Repeat with all cookies until you have made all the whoopie pies. If you’re using sprinkles, hold each whoopie pie and roll or sprinkle the jimmies into the exposed filling until it’s nicely coated. Refrigerate for at least 1 hour before serving to allow the filling to set.