Irish Cream Whoopie Pies

Ah, whoopie pies... decadent cookies, sandwiched together with utter sweetness, beckoning to be devoured. I just can't seem to get enough of them! I've made three variations in the last month, and I'm swooning over the heavenly goodness that continues to find its way out of my oven. In celebration of St. Patrick's Day (and my love for Baileys!), I decided to try an Irish Cream Whoopie Pie.

I adapted the cookie portion from the chocolate pumpkin whoopies I made in the fall. Then, I whipped up a delightful Baileys buttercream filling.

These turned out SO good... they're intoxicating!

Ingredients
Yields about 20 whoopie pies
For the cookies: 
1 3/4 cups all-purpose flour
3/4 cup unsweetened cocoa powder
1 1/2 tsp baking soda
1/2 tsp salt
5 tbsp unsalted butter, softened
1/2 cup granulated sugar
1/2 cup packed dark-brown sugar
1 large egg
1 cup Baileys Irish Cream
1 tsp pure vanilla extract

For the filling:
12 tbsp (1 and 1/2 sticks) unsalted butter, softened
1 3/4 cups confectioners' sugar
1 1/2 - 2 tbsp Baileys Irish Cream

Directions
Preheat oven to 375°. Line baking sheet with non-stick baking mat or parchment paper; set aside.

In a medium bowl, whisk together flour, cocoa powder, baking soda, and salt; set aside.

In the bowl of an electric stand mixer, combine butter and both sugars. Using the paddle attachment, mix on medium/high speed until smooth, about 3 minutes. Add egg and mix until pale and fluffy, about 2 minutes. Adjust speed to low and gradually mix in half the flour mixture, then the Baileys and vanilla, and finish with the remaining flour mixture.

Drop tablespoonfuls onto prepared baking sheet, spacing 2 inches apart. Bake 10-12 minutes or until cookies spring back when lightly touched. Place baking sheet on wire rack and let cool 5-10 minutes. Remove cookies from baking sheet and transfer to wire rack to cool completely.

For the filling, combine butter and sugar in a large bowl. Beat with an electric mixer on medium speed until light and fluffy, about 3-5 minutes. Add Baileys and beat until combined. Transfer buttercream to a prepared pastry bag fitted with a large star tip.

To assemble, pipe filling on the flat sides of half the cookies then sandwich with remaining cookies.