Preheat oven to 350 degrees. Place brownie mix, eggs, oil and coffee in a large bowl. Stir 50 times with a large spoon, scraping the sides and bottom so everything gets mix in together. Add in the chopped M&M’s® Coffee Nut and fold in.
Pour mix into a greased 13x9 inch pan. Bake for 21-23 minutes until a toothpick inserted in the middle comes out almost clean. A little batter sticking is okay.
Place on a wire rack to cool completely.
Mocha frosting
Mix powdered sugar and cocoa powder in a small bowl, set aside.
Add butter to a large bowl, using a hand mixer, cream the butter until smooth. Slowly start adding in the sugar mixture a little at a time until fully incorporated, scraping the sides as needed. Add in the vanilla and the coffee, whip until light and fluffy about 3 minutes.
You can either frost the entire brownies now or pipe the individual pieces as shown here, garnish with more M&M’s® Coffee Nut, serve and enjoy!