Chocolate Chip Cookies

Method

1. Melt the butter in a 2-quart saucepan over low heat. Set aside to cool slightly.
2. Sift together the flour, salt, baking soda, and cornstarch onto parchment paper.
3. Pour the butter into your stand mixer's work bowl. Add the sugar and brown sugar and beat with the paddle attachment on medium speed for 2 minutes.
4. Meanwhile, whisk together the whole egg, egg yolk, cold espresso, and vanilla extract in a measuring cup.
5. Reduce the mixer speed and slowly add the egg mixture. Mix until thoroughly combined, about 30 seconds.
6. Using the parchment paper as a slide, gradually integrate the dry ingredients, stopping a couple of times to scrape down the sides of the bowl.
7. Once the flour is worked in, drop the speed to low and add the chocolate chips.
8. Chill the dough for 1 hour.
9. Preheat the oven to 375°F (190°C) and place racks in the top third and bottom third of the oven.
10. Scoop the dough into 1/4 cup portions onto parchment-lined sheet pans; flatten each ball of dough. Bake 2 sheets at a time for 15 minutes, rotating the pans halfway through.
11. Remove from the oven, slide the parchment with the cookies onto a cooling rack, and wait at least 5 minutes before devouring.