1sleeveThin Mint or other chocolate mint cookies (about 20 cookies)
Preheat oven to 325˚F. Grease then line a 9" square cake pan with parchment paper. Set aside.
In a food processor (or you can do this the old fashioned way in a large freezer bag with a rolling pin or other hard glass), pulse Thin Mint cookies until the cookies become fine sand.
In a large bowl, combine the brownie mix*, water, oil, eggs, and Thin Mint cookies. Stir until just combined. Bake for 30-35 minutes or until middle of brownies comes out clean when poked with a toothpick.
*Brownie boxed mixes are usually very similar -- but be sure to look on the back of the package to make sure to include the proper ratios of oil, eggs, and water. I'm using our favorite Ghirardelli double chocolate brownie mix here we buy at Costco. Storage: Store in an airtight container at room temperature. Brownies are delicious for 3-4 days.