Preheat oven to 350.

In a medium bowl, whisk together the flour, baking soda, baking powder, salt, cinnamon, ginger, and nutmeg. Set aside. In a large bowl, beat together the brown sugar, white sugar, and oil. Add the pumpkin puree and mix well. Add the vanilla and eggs and mix well. Slowly add in the flour mixture and mix until combined.

Using a 1 tablespoon scoop or a 1/2 tablespoon measure, drop the batter onto a baking sheet (lined, if possible, but not necessary), leaving about 1" between the batter. Try to keep the batter as circular as possible. Bake for 10-14 minutes or until the tops are done and a toothpick inserted into the middle of one of the cakes comes out clean. Remove from oven and allow to cool for 5 minutes on the pan and then transfer to a cooling rack.

To prepare the filling, beat the butter on high for 1-2 minutes until smooth and fluffy. Add the cream cheese and beat until smooth. Add the powdered sugar, maple, and vanilla and beat until combined. Transfer to a large Ziploc bag and cut 1/2"-1" off the corner.

Flip the cakes over on a flat surface. Squeeze about 2-3 tablespoons of filling per large whoopie pie (less if you used a 1/2 tablespoon measure) onto every other cake. Top each pie with the remaining cakes. Serve immediately if possible; otherwise, these can be refrigerated in an airtight container. Makes about 30 large whoopie pies.