Melt butter in a microwave safe bowl, 30 second intervals. Once melted add vanilla and nut milk stirring until combined. Add all dry ingredients into wet and stir well, removing all clumps. Crack in your egg and mix until no egg shows. Top with chocolate chips if desired and microwave for 1 minute to 1:30. Brownie should be fully set with no raw batter showing. Feel free to top with heavy cream or a low carb ice cream.