By Reddit user u/Sneakerhead157
Start off by browning the butter in a pan and melting the brown sugar in a pot.
Then add the butter to the melted sugar while stirring to create a sauce similar to butterscotch.
After it’s ready and it cools down you can add the espresso and the white sugar.
Let it cool down more and add the egg. MIX MIX MIX.
Then the vanilla and everything else.
Baking at 170 Celsius or 340 F for approx 9 minutes.
Top with your favourite flaky salt.
When shaping them you have to make them pretty flat since they don’t spread a lot.
Makes 10-12 cookies based on size.
Source:
https://www.reddit.com/r/Cookies/s/fyBPlcLMYE