Start by melting your butter in the microwave. Butter should just be melted, not boiling.
Add sugars, vanilla and salt. Stir to combine.
Separate your egg and add the yolk only to your cup. Stir to combine.
Add flour, then stir again. Measure a scant, slightly less than full, ¼ cup of all-purpose flour.
Add the chocolate chips, and give a final stir. Now your mixture will look like cookie dough.
Cook in microwave 40-60 seconds, start checking for doneness at 40 seconds. Mine takes 50 seconds. Do not cook past one minute, just like a regular cookie, this will continue cooking as it cools. If the cookie is dry or cake like, try less time.
Serve warm.