Adapted from Food Network Magazine, October 2011
Preheat oven to 400. Grease 3 cookie sheets.
Using a stand mixer, beat butter and sugar until fluffy. Beat in the egg and buttermilk and vanilla.
Gradually add the dry ingredients, mixing until just combined.
Using a medium cookie scoop, scoop even amounts (so that the sandwiches will be symmetrical) of batter onto prepared cookie sheets.
Bake 8 minutes. Don not over bake. Allow to cool 2 minutes then remove to racks and cool completely.
!To make the filling:
Beat the cream cheese and butter until smooth. Slowly beat in the powdered sugar until smooth. Add the pumpkin and cinnamon and beat until completely incorporated.
!To assemble whoopie pies:
Spread a tablespoon full of filling on the flat side of a cake then top with another cake, pressing down until the filling just reaches the edges but doesn't ooze out.Repeat with remaining cake and filling.