Melt the butter to a microwave-safe mug and melt in 30-second increments, stirring in between, until completely liquefied.
2 tablespoons unsalted butter
Add the sugar and stir with a fork until well combined.
2 tablespoons light brown sugar
Add the flour, baking powder, salt, milk, vanilla extract and use your fork to stir until the batter is smooth and free from lumps. Make sure you integrate any dry ingredients that may have gotten stuck to the sides or corners of the mug.
¼ cup all-purpose flour, ¼ teaspoon baking powder, ⅛ teaspoon salt, 3 tablespoons milk (preferably at room temperature), ½ teaspoon vanilla extract
Asses the consistency of your batter. Ideally, it should be like pancake batter—not too thick, but thick enough so that the chocolate chips can float on top. If the batter is too thin, you can add up to 2 more teaspoons of flour if needed.
Stir in about 3/4 of the chocolate chips, then sprinkle the remaining chocolate chips on top.
¼ cup chocolate chips
Microwave for 80 seconds, then allow the mug cake to sit in the microwave for an additional 1 minute. Enjoy!