Add 1 tbsp butter to a microwave-safe cup or mug and microwave for 10 seconds until it melts. No need to heat or boil, just make sure it's melted.
Add the 1 tbsp white sugar, 1 tbsp brown sugar, pinch of salt, and 2 drops vanilla to this. Mix well.
Separate an egg and add just the egg yolk to the above. Mix well to combine.
Add the 2 heaping tbsp of flour and mix until no streaks of flour remain. The mixture will be fairly thick.
Add the 2 tbsp chocolate chips to this and fold until well combined. I added some more chips on top to make the cookie look pretty when done.
Microwave on high (mine is a 1100W microwave) for 45-50 seconds. I stopped at 45 seconds and that was perfect. The top will still be a bit fudgy but remember that the cookie will continue to cook after you take it out.
That's it! Scoop out with a spoon and enjoy