Add 2 tablespoons of butter to a mug and melt it in the microwave.
Add 1 tablespoon of white sugar to the melted butter.
Add 2 tablespoons of brown sugar.
Mix the ingredients well.
Add 1 tablespoon of milk.
Add a splash of vanilla extract.
Mix again until combined.
Add ¼ cup of flour.
Add an additional 2 tablespoons of flour.
Add ¼ teaspoon of baking soda.
Add ⅛ teaspoon of salt.
Mix all ingredients until a dough forms.
Add chocolate chips and mix them into the dough.
Place a few more chocolate chips on top of the dough.
Microwave the mug cookie for 45 seconds.
Check if the cookie is done by inserting a toothpick; it should come out clean.
