What you need:
I box cake mix
1/2 cup oil
1-1/3 up water
1 can icing (or your own homemade icing)
1/2 cup pureed pumpkin
1 cup powdered sugar
What to do:
Preheat oven to 35F.
In a large bowl, mix the cake mix, eggs, water and oil. Mix until everything is incorporated.
Using a whoopie pie baking sheet, fill each cup with about 2 tablespoons of batter.
If you don't have a whoopie pie baking sheet, use a regular baking sheet lined with parchment paper. Dropping 2 tablespoons of batter on a circle on the sheet for each pie.
Bake for 8-10 minutes.
Remove from oven, and place on cooling rack to cool.
Once cakes are cooled, start making the filling.
Combine, 1 can of vanilla frosting, 1/2 pureed pumpkin, and 1/2 cup powdered sugar. Depending on how thick you want the filling you may want to add the remaining sugar.
Mix until well combined. Spoon Icing onto the flat side of one cake pie and then press another cake pie ontop of the filling to make the sandwich