Preheat the Oven: Preheat the oven to 350°F (175°C). Line a cupcake tin with paper liners.

Combine Dry Ingredients: In a bowl, whisk together the flour, cocoa powder, baking powder, baking soda, and salt. Set aside.

Cream Butter and Sugar: In a separate bowl, cream together the softened butter and sugar until light and fluffy.

Add Eggs and Vanilla: Add the eggs one at a time, beating well after each addition. Mix in the vanilla extract.

Combine Wet and Dry Ingredients: Gradually add the dry ingredient mixture and the buttermilk to the butter mixture, starting and ending with the dry ingredients.

Fill Cupcake Liners: Divide the batter evenly among the cupcake liners, filling each about two-thirds full.

Bake: Bake for 18-20 minutes or until a toothpick inserted into the center of a cupcake comes out clean. Let cool completely on a wire rack.

Decorate: Once cooled, pipe the chocolate frosting onto each cupcake. Split the chocolate sandwich cookies and use the halves with cream as bat wings by placing them into the frosting on each side of the cupcake. Add candy eyes to complete the bat face.