For the Brownies:

1. Preheat oven to 350°F. Spray 24 mini muffin cups with nonstick spray and set aside.
2. In a large bowl, whisk butter and cocoa powder together until cocoa is dissolved and mixture is thick.
3. Stir in sugar until combined.
4. Stir in eggs, mixing until combined.
5. Add vanilla and mint extracts.
6. Add flour, stirring just until no white streaks remain in batter.
7. Fold in melted candy bars.
8. Use a small cookie scoop to divide batter in prepared muffin.
9. Bake for about 12-15 minutes, or until a toothpick inserted in the center comes out with fudgy crumbs, but not raw batter.
10. Let cool slightly, about 15 minutes, then use a sharp knife to loosen brownie bites and remove from pan. Let cool completely.

For the Buttercream:

1. In the bowl of your mixer, beat butter, extracts, and cream on medium-low speed until combined.
2. With the mixer on low, slowly add powdered sugar, beating until just barely mixed. Add food coloring and increase speed to high – beat for one minute.
3. Generously frost or pipe frosting on brownie bites.

To Serve:

1. Sprinkle with chocolate sprinkles or chocolate cookie crumbs, if desired.