I love whoopie pies, they are like cupcakes turned inside out. I make mine ridiculously large using a muffin top pan (remember when those were big back in the mid 90's?). The rewards of your efforts here are major, but you have to keep a few things in mind when making these. First off, you have to line the wells with parchment paper rounds. I purchased a large round punch years ago and use that which covers the surface 75% of the way and that is good enough. Two, you need to spray your wells - I always use Bak-klene which uses cornstarch to help release which means no grimey, brown baking sheets years down the road. Third, use a cookie/ice cream scoop to ensure they are all the same size. For this recipe you will want to actually use a little bit of a heaping scoop and lightly spread it around. This recipe makes 12 whoopie pies.
1/2 cup butter or butter-flavored shortening
2 cups sugar
1/2 tsp salt
2 tsp. vanilla
2 tsp. baking soda
2 large eggs
3/4 cup cocoa powder
1 3/4 cup buttermilk
1 3/4 cup flour
In the bowl of a mixer with paddle attachment, cream butter, sugar, salt, vanilla and baking soda together until combined. Add eggs and mix on low to combine, then add cocoa powder and mix on low. Add buttermilk and mix, scraping edges of bowl to make sure everything is incorporated. Add flour and mix on low until combined.
Preheat oven to 350 degrees. Place 2, slightly-heaping tablespoons of batter into the center of each well of a muffin top pan that has been sprayed and lined with parchment. Bake for 11 minutes, rotating pan half-way through.
1 stick unsalted butter
1/2 stick regular shortening
2 cups powdered sugar
1/2 - 7 oz. jar marshmallow cream
2 tbsp. vanilla-bean paste.
Combine in the bowl of an electric mixer with the paddle attachment and mix until creamy, scraping bowl if necessary. Place 2 heaping tablespoons of filling onto one side of whoopie pie, spreading mixture across surface and top with second half of whoopie pie. Enjoy!