Preparation Steps

• Brown the butter: In a light-colored saucepan over medium heat, melt the butter and cook, stirring, until it turns deep golden with toasty bits on the bottom, 4–6 minutes. Scrape into a large mixing bowl and let cool until warm, not hot, about 8–10 minutes.
• Whisk in sugars: Add the brown sugar and granulated sugar to the warm browned butter. Whisk vigorously for 1 minute, rest 2 minutes, then whisk again for 30 seconds until slightly thickened and glossy.
• Add egg and vanilla: Whisk in the egg and vanilla until the mixture looks smooth and shiny, about 30–45 seconds.
• Combine dry ingredients: In a separate bowl, whisk the flour, baking soda, salt, cornstarch, and espresso powder. Add the dry mixture to the wet ingredients and fold with a spatula just until a few dry streaks remain.
• Fold in chocolate: Add the chocolate chips and mix just until evenly distributed. Cover the bowl and chill the dough for 15–20 minutes to firm slightly.
• Preheat and prep pans: While the dough chills, heat the oven to 375°F (190°C). Line two baking sheets with parchment paper.
• Portion: Scoop about 2 tablespoons of dough per cookie (around 40g), spacing 2 inches apart. For thicker cookies, shape scoops taller than they are wide.
• Bake: Bake 8–10 minutes, rotating the pan halfway, until edges are set and centers look slightly underdone. For crinkly edges, tap the pan once on the rack during the last 2 minutes of baking.
• Cool: Let cookies rest on the sheet for 5 minutes, then transfer to a wire rack to finish cooling.