These Pumpkin Whoopie pies have a cream cheese filling inside.
Preheat oven to 350°F. Line a cookie sheet with parchment paper or spray with cooking spray.
In a large bowl, add the cake mix, butter, pumpkin, pumpkin pie spice, eggs, and milk. Mix slowly for 30 seconds or until combined, then beat for 1-2 minutes. Batter will be on the wet side.
Drop tablespoon-sized dollops onto the cookie sheet. Try to make sure that they are all the same size.
Bake for 10-11 minutes. Let them cool completely.
To make the frosting: Combine the cream cheese and butter in a medium bowl with an electric mixer until smooth. Add the sugar and mix at low speed until combined. Stir in the vanilla and mix again. You may need to add a little milk to make it spreadable if your butter wasn't soft enough.
Frost a cookie with a dollop of cream cheese frosting and top with another cookie. Store in an airtight container and refrigerate.