1 box brownie mix, plus additional ingredients called for on the package (I used an 18-ounce box of Ghirardelli brownie mix, but anything similar will work fine)
2 tablespoons bourbon

For the Frosting:*
3 tablespoons butter, softened
1 ½ cups powdered sugar, sifted
2-4 teaspoons bourbon, plus additional, as needed
¼ teaspoon vanilla
Pinch of salt
Optional: Sprinkles