Haven’t made these yet, but I need to type the recipe up somewhere. From the Penzey’s catalog.
1 egg
1/3 cup vegetable oil
1 cup sugar
2 cups flour
1/2 cup cocoa powder
1 tsp baking soda
1/4 tsp salt
3/4 cup buttermilk
1 tsp vanilla extract
filling:
1 stick butter, room temp
1 cup powdered sugar, sifted
1 cup marshmallow fluff
1 tsp vanilla extract
Preheat oven to 350F. Grease two large cookie sheets, set aside. In large bowl, beat the egg and oil. Gradually add the sugar and keep beating till pale yellow. In another bowl, sift the flour, cocoa, baking soda and salt. In a measuring cup, combine the buttermilk and vanilla. While mixing, alternate adding the dry ingredients and buttermilk to the egg and sugar, beginning and ending with the dry ingredients. Drop the batter by tablespoons onto cookie sheets. These will spread a lot, so make 6 cookies per sheet at a time. Bake 8-10 mins until the top springs back when lightly touched. Remove to wire racks to cool. When cool, spread filling between two cookies to make sammiches.
For the filling, combine all ingredients in a medium bowl and beat until light and fluffy.