Mint julep brownies

We were running low on cookies, which my spouse would live on if he could, and with the next store trip planned for Wednesday, I decided to make brownies. I wanted something different than a typical brownie recipe, though, so I pulled out a copy of a book I hadn't looked at in a while – the Rosie's Bakery Chocolate-Packed, Jam-Filled, Butter-Rich, No-Holds-Barred Cookie Book – and lo and behold, there were bourbon brownies. What could be better? But the spouse took one look at them and said, you know, if you made a mint frosting instead of the ganache the recipe calls for, we could have mint julep brownies. So I did. And they are gooooood. So I'm sharing. 

( recipe, after the cut )