These are minty homemade versions of the iconic “whoopie pie.” Green food coloring optional.
Mint Chocolate Cookies:
1-1/4 Cups flour
3/4 Cup unsweetened cocoa powder
1-1/2 tsp baking soda
1/2 tsp baking powder
1/2 tsp salt
9 Tbsp unsalted butter, room temperature (1 stick + 1 Tbsp)
1 Cup sugar
1 Cup buttermilk
1 tsp Peppermint Extract
Irish Cream Mint Filling:
2 Cups confectioners’ sugar, sifted
4 Tbsp unsalted butter, room temperature
3 Tbsp Bailey’s Irish cream
2 tsp Vanilla Extract or Vanilla Paste
1/2 tsp Peppermint Extract
1/2 tsp salt
green gel food coloring (optional)
Make the “whoopie pie” cookies — Sift together the dry ingredients: flour, cocoa powder, baking soda, baking powder and salt, in a medium bowl. Set aside.
Using a stand mixer, cream together the 9 Tbsp butter and sugar until fluffy, about 3 min on lowest speed setting. Add the egg, followed by the buttermilk and peppermint extract. Make sure to periodically scrape the sides of the mixing bowl with a spatula, and mix ingredients until well combined. Note that batter may look curdled, but don’t worry. Add the dry ingredients, a little at a time, to the mixture until just combined. Refrigerate batter for 30 min.
Preheat the oven to 350F, and line 2 baking sheets with parchment paper.
Using a cookie scoop, or with a couple of soup spoons, scoop approx 1-1/2 Tbsp-size scoops of dough onto the prepared baking sheets. Leave 2 in between each cookie for dough to spread out while baking. Bake each sheet of cookies separately, about 10 min each, or until the cookies spring back when lightly pressed.
Transfer the baking sheet to a wire rack to cool 5 min before removing them from the sheet and allowing cookies to cool directly on the wire rack. Repeat with the second cookie sheet.
Make the irish cream mint filling: Cream together the powdered (confectioners’ ) sugar and butter with a heavy mixer and mixing bowl. Mixture will have crumbly consistency. Add the Bailey’s Irish Cream, vanilla, peppermint extract and salt. Increase mixer speed and whip until light, fluffy and smooth, about 3 min.
If you want green filling (for St. Patrick’s Day) – Add a tiny glob of green gel food coloring and mix to blend color throughout the filling.
Assemble the “whoopie pies:” Sort through the cooled cookies, and pair them with similarly-sized mates. Using a pastry bag or other tool, pipe frosting on the flat (under) side of one cookie and then sandwich the cookies together, pressing flat sides together, and smooshing the filling to the edges.
Use a small butter knife to wipe away excess filling, if the buttercream seems to stick out too far beyond the edges of the cookie sandwich.
Can be covered and refrigerated for several hours, but should be served the day they are made.