Step 1

Preheat oven to 325 degrees. Mix butter and brown sugar. Whisk in egg yolk and vanilla.

Step 2

Stir in flour, salt, and baking soda. Stir in chocolate chips. Divide between two 8-ounce ramekins and press gently to fill the bottom of each (see notes if you don’t have a ramekin).

Step 3

Bake for 18-22 minutes (18 for underbaked, 20 for semi-baked, 22 for almost fully baked). Allow to cool for a few minutes so they firm up a bit, but definitely, obviously, of course, eat while warm, ideally with some vanilla ice cream. YUM!