Instructions

1. Place a rack in the upper third of the oven and preheat the oven to 350 degrees F. Line a baking sheet with parchment paper and set it to the side.
2. In a small saucepan, melt butter until bubbling. Remove from the heat and whisk in the brown sugar until it feels like the sugar has started to dissolve in the butter. If it feels like the butter is separating from the sugar, that’s ok – keep going. Whisk in the powdered sugar. This might feel like a clumpy mess, but I promise the lumps will whisk out.
3. Whisk in the egg yolk and splash of vanilla until emulsified, smooth and glossy.
4. Add flour, cocoa powder, salt, and baking soda and stir with a spatula until no dry bits remain.
5. Add the chopped Reese’s and work quickly, because the chocolate will start to melt in the warm pan.
6. Fold the Reese’s throughout the dough and quickly dollop in two globs (of course you could do three or four globs) on the prepared baking sheet. Dot with a few more Reese’s and sprinkle with extra sea salt.
7. Bake for 12-14 minutes until golden around the edges and still slightly soft in the center. Remove from the oven and see how long you can let them cook before eating them straight off the baking sheet.