Ingredients
Equipment
Method
Mix the dry ingredients
- Whisk all-purpose flour, cornstarch, baking soda, and salt in a bowl until evenly combined and no dry streaks remain.
Build the wet mixture
- Whisk the melted unsalted butter with brown sugar and granulated sugar until smooth, then whisk in the egg, egg yolk, and vanilla extract until glossy.
Form the dough
- Stir the dry ingredients into the wet mixture until a soft dough forms, then fold in the semi-sweet chocolate chips just until distributed.
Chill the dough
- Cover the dough and refrigerate for 30 minutes so it firms up and bakes thick with a tender center.
Preheat and portion
- Preheat the oven to 325F and line baking sheets with parchment for easy release and even browning.
Shape the cookies
- Scoop and roll the dough into 3-tablespoon balls, then place them 2 inches apart on the baking sheets.
Bake
- Bake at 325F for 10-12 minutes, until the edges are set and the centers look pale and puffy.
Cool to finish setting
- Cool the cookies for 10 minutes on the sheet so the centers finish setting while the outsides stay tender.
Notes
Pro tip: keep the melted butter slightly cooled before whisking so the sugars don’t scramble the eggs, helping the dough stay thick. Store cookies in an airtight container at room temperature for 3 days, or refrigerate for up to 5 days; freeze baked cookies up to 2 months. For a lower-sugar option, use a 1:1 portion of light brown sugar and reduce granulated sugar to 2 tbsp (texture will be a touch softer).