Chocolate Chip Cookies

Ingredients

• 227 g unsalted butter, 2 sticks (16 tablespoons)
• 200 g dark brown sugar, 1 cup, packed
• 100 g granulated sugar, 1/2 cup
• 2 large eggs, cold is fine
• 2 tsp vanilla extract
• 290 g all-purpose flour, about 2 1/4 cups, spooned and leveled
• 1 tsp baking soda
• 1½ tsp Diamond Crystal kosher salt
• 280 g bittersweet chocolate, 10 oz bars, 60 to 70%, chopped into rough 1/2-inch pieces, crumbs included
• flaky sea salt, for the tops (optional)

The salt amounts here are for Diamond Crystal kosher salt. If you have Morton kosher salt, use a little over half as much, because its grains are denser and saltier by the spoon.

Steps

1. Melt the butter in a light-colored saucepan over medium heat. It will foam, go quiet, and then the solids on the bottom will turn hazelnut brown and smell like toasted nuts, 5 to 7 minutes in all. Swirl the pan as it gets close; it goes from brown to burnt in under a minute. Scrape everything, browned bits included, into a large bowl.
2. Whisk the brown sugar and granulated sugar into the hot butter. Leave it for 10 minutes, until it feels warm but not hot on a fingertip, so it doesn't cook the eggs.
3. Whisk in the eggs and vanilla until the mixture turns glossy and slightly thick, about 30 seconds. In another bowl, whisk the flour, baking soda and kosher salt.
4. Add the flour mixture to the butter and fold with a spatula until only a few dry streaks remain. Add the chocolate and fold until no flour shows. The dough will be soft and greasy at this point.
5. Cover and refrigerate for at least 2 hours. Overnight, or up to 3 days, is better: the cookies spread less and bake up thicker and darker.
6. Heat the oven to 350°F with a rack in the middle and line a baking sheet with parchment. Scoop the cold dough into 50 g balls, about 3 tablespoons each, and set 8 on the sheet with 3 inches between them. Keep the rest of the dough in the fridge. Sprinkle each ball with a few flakes of flaky salt, if using.
7. Bake one sheet at a time, turning it halfway, until the edges are golden and set and the centers are puffed and pale and look a minute short of done, 12 to 14 minutes.
8. Leave them on the sheet for 5 minutes to firm up, then move them to a rack. Bake the rest of the dough the same way, on a cool sheet each time.

Notes

Scooped balls freeze for up to 3 months; bake from frozen and add 2 minutes. Baked cookies keep in a tin for 3 days. If you'd rather use chips, the cookies come out tidier, with fewer melted pockets.