Preheat the oven to 350 degrees F (175 degrees C). Grease a 10x15-inch baking pan.

Stir together both brownie mixes, vegetable oil, eggs, and water in a large bowl until well blended. Pour batter into the prepared baking pan.

Bake in the preheated oven until toothpick inserted in the center comes out clean, 30 to 35 minutes. Let cool, about 20 minutes.

While brownies are cooling, combine powdered sugar, butter, water, peppermint extract, and food coloring in a large bowl; beat with an electric mixer until smooth. Spread mint frosting on top of cooled brownies.

Place chocolate chips and butter in a microwave-safe bowl. Microwave on high for 1 minute, stir, and microwave again in 30 second intervals, stirring after each interval, until melted. Add peppermint extract to taste and spread on top of mint frosting. Refrigerate until frosting and topping layers are set.