Duncan Hines Mug Cakes Walnut Brownie Mix treats you to a convenient individual dessert that cooks in about a minute. The rich chocolate mug brownie features walnuts for an indulgent taste. Create a quick, sweet after-dinner treat with this walnut brownie mug mix. Simple prep means you can enjoy this mug dessert quickly. Just add two tablespoons of water or milk to an individual pouch of brownie mix in a microwavable mug, microwave on high for 55 seconds and let cool. From decadent brownie mix to single serve desserts, Duncan Hines has you covered when you’re ready to bake and create.