Halloween Whoopie Pies

Instructions

1. 1
   Preheat oven to 350°F (175°C). Line two baking sheets with parchment paper.
2. 2
   In a medium bowl, whisk together flour, cocoa powder, baking soda, baking powder, and salt.
3. 3
   In a large bowl, beat butter and brown sugar until light and creamy. Add egg and vanilla; mix until smooth.
4. 4
   Gradually add dry ingredients to the wet mixture, alternating with buttermilk. Mix until just combined.
5. 5
   Drop rounded tablespoons of batter onto prepared sheets, spacing 2 inches apart.
6. 6
   Bake for 10-12 minutes or until tops spring back when touched. Cool 5 minutes, then transfer to a wire rack.
7. 7
   For the filling, beat together marshmallow creme and softened butter until smooth. Add powdered sugar and vanilla, beating until fluffy. Divide and color as desired.
8. 8
   Spread or pipe filling onto half the cooled cookies. Top with remaining cookies. Roll edges in sprinkles, if using.