Make the chocolate ganache filling: Put chocolate, cream, sugar, and salt in a small bowl.

Heat in the microwave until it barely starts to boil. Approximately 1-2 minutes.

Slowly and carefully stir the mixture until the cream fully incorporates into the chocolate mixture and the sugar dissolves. Add the butter in small pieces and stir until it has melted and combined completely with the chocolate.

Transfer to a plastic food storage bag, squeezing the air out completely as you seal it. Let cool and thicken until it is as thick as peanut butter. It will take several hours at room temperature or 1-2 hours in the fridge. If you live in a warm climate, it may not thicken up enough at room temp.

Make the pumpkin whoopie pies: Preheat the oven to 375°F. Line a baking sheet with parchment paper.

In a large bowl, blend butter and sugar. Add egg, then pumpkin, and blend until well combined. Add flour, baking soda, baking powder, cinnamon, and salt. Mix by hand until combined.

Put batter into a gallon-sized plastic food storage bag. Cut ½ inch off one corner. Pipe 1-2 inch circles of batter (depending on how large you’d like them to be) onto the baking sheet. (I draw circles on the underside of the parchment as a guide for the batter.)

Bake for 12-15 minutes, until whoopies are slightly browned. Remove from the oven and let cool completely.

Cut ½ inch off the corner of the ganache bag. Pipe the ganache onto the flat side of one cookie. Use another cookie to create the “sandwich” or whoopie pie. Repeat until all whoopie pies are made.