In a large bowl, combine the butter and sugar and beat until light and fluffy. Add half of the flour mixture and beat on low speed until incorporated.

Add the eggs, coffee, and vanilla extract and mix on low speed until fully combined. Add the remaining flour mixture and beat for 1-2 minutes until fully mixed. Cover and chill dough in refrigerator until firm, 2-3 hours.

Preheat oven to 325ºF. Line two baking sheets parchment paper and set aside.

Using a small cookie scoop, place 6 portions of cookie dough onto each of the prepared baking sheets.

Bake for 10-12 minutes until the edges are set and the tops are soft.

Cool the cookies on the baking sheet for 5 minutes, then transfer to wire racks to cool completely. Repeat with remaining dough.

Beat the butter on medium speed until creamy.

Add the powdered sugar and beat on medium speed until combined.

Add the coffee and vanilla extract and beat until fully incorporated.

Beat on high speed until fluffy.

Use an offset spatula to spread 1-2 tablespoons of coffee buttercream on top of each cooled cookie.

Add 3 chocolate-covered espresso beans and desired amount of cacao nibs to the top of each cookie.