Step 1:
1- in a bowl, mix together the butter, sugars, vanilla, and egg yolk. Step 2:
2- add in the flour and salt. Mix until combined. Step 3:
3- add in the chocolate chips. Step 4:
4- put the dough into a small microwaveable bowl, ramekin, or coffee cup. Step 5:
5- microwave for 40-60 seconds or until the cookie looks done.