Ingredients:

  • 1/2 cup (113g) unsalted butter, melted and cooled
  • 3/4 cup (150g) light brown sugar, packed
  • 1/4 cup (50g) granulated sugar
  • 1 large egg, room temperature
  • 2 tsp vanilla extract
  • 1/2 cup (45g) Dutch-processed cocoa powder
  • 1 1/3 cups (170g) all-purpose flour
  • 1 tsp cornstarch
  • 1/2 tsp baking soda
  • 1/4 tsp fine sea salt
  • 1/2 cup (90g) semi-sweet chocolate chips
  • 12 large marshmallows, cut in half crosswise
  • 1/4 cup chocolate sauce for drizzling

Instructions:

  1. Melt the butter. Let the 1/2 cup butter cool slightly in a large bowl. Note: If it's boiling hot, it might scramble your egg.
  2. Whisk in sugars. Combine the brown and white sugars with the butter until the mixture looks like wet sand.
  3. Add wet ingredients. Incorporate the egg and vanilla extract, whisking until the mixture is glossy and smooth.
  4. Sift the drys. Whisk together flour, cocoa, cornstarch, baking soda, and salt. Cook 2 mins as you stir these into the wet mix until no flour streaks remain.
  5. Fold in chips. Stir in the semi sweet chocolate chips until evenly distributed throughout the velvety dough.
  6. Chill the dough. Refrigerate for at least 30 minutes. Wait until the dough is firm to the touch.
  7. Scoop and bake. Preheat oven to 350°F (180°C). Space dough balls 2 inches apart. Bake for 10 minutes until edges are set but center is soft.
  8. The Marshmallow Cap. Quickly place half a marshmallow (cut side down) on each cookie and return to the oven.
  9. Final Toast. Bake for 1-2 more minutes until marshmallows are puffed and slightly melty.
  10. Drizzle and Cool. Let them cool on the pan for 5 minutes, then drizzle with chocolate sauce until they look like a coffee shop treat.