Preheat oven to 325°F.
Combine egg, butter, water in a bowl. Add box mix, stir until the ingredients are combined, and lumps are gone. Add chips and 1 cup of nuts, and pour mixture into the greased 9x13 baking pan.
Bake for 40-45 minutes. Let cool for 15 minutes and place the cake on wire cooling rack.
Frost brownie with butter cream frosting. Heat or microwave chocolate frosting for easy pouring. Pour 2 oz. chocolate frosting over butter cream layer.
Use a fork to blend two frostings for a marbled appearance, to desired pattern. Sprinkle brownie with remaining nuts.
Drizzle remaining chocolate frosting over the butter cream.
Put the brownie in the freezer to cool. Allow 10 minutes, cut and serve.
Submitted by: TanyaH
