Stir in heavy cream until thick brownie batter forms.
Microwave anywhere from 30-90 seconds to texture desired (less for fudgy brownies, longer time for cake-like)
Serve warm topped with whipped cream, if desired.
Brownie can be made in a coffee mug, ramekin, or any similar sized microwavable dish.To make the recipe egg-free, use a fiber syrup in place of the sweetener and omit the egg. Or a psyllium or flax egg can be used with granular sweetener.