Whoopie Pies:

1. Preheat oven to 325°F and line a baking sheet(s) with parchment paper or spray with no-stick spray; set aside.
2. In a medium bowl, whisk together the flour, cocoa powder, baking soda, baking powder and salt; set aside.
3. In the bowl of a mixer, add the shortening, butter, granulated sugar, brown sugar and molasses.
4. Cream on med-high speed for 3 minutes, scraping the bowl as needed, or until well blended.
5. Add the egg and vanilla and blend on medium speed.
6. On low speed, alternate adding the flour mixture and the stout, until well blended.
7. Scoop 2 tablespoons of batter onto the prepared baking sheet(s), leaving at least 2 inches in between each scoop.
8. Bake for 9-10 minutes.
9. Allow to cool on the baking sheet.

Filling:

1. In the bowl of a mixer, whip the shortening, marshmallow fluff and salt until well blended.
2. Slowly add the powdered sugar followed by the extracts and food coloring, if using.
3. Dollop about two tablespoons of filling on the bottoms of half the cooled whoopie pies.
4. Top with another whoopie pie to make a sandwich and press gently to spread the filling to the edges.