Ingredients
Method
- Stir the melted butter with the granulated sugar and brown sugar until smooth and glossy, about 1 minute.
- Whisk in the egg, egg yolk, and vanilla extract until pale and slightly thick, about 30 seconds.
- Preheat the oven to 350°F (175°C), then sift in the flour, cocoa powder, baking soda, and salt and stir just until combined.
- Fold in the semisweet and milk chocolate chips, then scoop into 18 balls of dough.
- Bake at 350°F (175°C) for 11 to 12 minutes, until the edges are set and the centers still look soft, then rest on the pan for 3 minutes before serving.
Notes
If you only have one baking sheet, scoop all the dough onto parchment paper first and slide the cookies onto the hot pan in batches, that way the rest of the dough isn't sitting out too long. The dough also keeps in the fridge for up to 3 days if you want to bake fresh cookies over several evenings instead of all at once.
