Preheat your oven to 350 degrees Fahrenheit.

Prepare an 8-inch or 9-inch baking pan by lining it with parchment paper or spraying it with non-stick cooking spray.

Follow the instructions on the brownie mix package to prepare the brownie batter. Typically, this involves mixing the brownie mix with eggs, water, and the softened butter until well combined.

Pour the prepared brownie mixture into the lined or greased pan, spreading it evenly.

Bake for about 25-30 minutes, checking for doneness with a toothpick; it should come out clean or with a few moist crumbs attached.

Remove from the oven and allow to cool completely, which may take about 30 minutes to an hour.

In a mixing bowl, combine the softened butter, powdered sugar, milk, and peppermint extract. Blend until light and fluffy.

Add a drop of green food coloring and mix until evenly distributed.

In a microwave-safe bowl, combine the butter and semi-sweet chocolate chips. Heat in 45-second increments, stirring until smooth and fully melted.

Spread the mint cream layer evenly over the cooled brownies.

Pour the melted chocolate topping over the mint layer and allow it to cascade down the sides.

Optional: Finely crush some Andes mints and sprinkle them on top.

Let the brownies set at room temperature or refrigerate for about 30 minutes for quicker setting.

Lift the brownies out of the pan using the parchment paper and cut into squares.