Ingredients
2 1/2 sticks unsalted butter
2 cups packed light-brown sugar
1/2 teaspoon baking soda
3/4 teaspoon fine sea salt
3 large egg yolks, room temperature
2 teaspoons pure vanilla extract
3/4 cup discard from Sourdough Starter
2 1/2 cups unbleached organic all-purpose flour
10 ounces semisweet chocolate, coarsely chopped, or chocolate chips
Preparation
Heat butter in a saucepan over medium until it simmers and foam rises to surface. Continue cooking until solids sink to bottom and turn golden brown, 5 to 8 minutes. Pour into a mixing bowl, scraping in browned solids as well. Let cool 30 minutes.
Beat butter with sugar, baking soda, and salt on medium speed until well combined, about 2 minutes. Add egg yolks and vanilla and continue beating another 1 minute. Beat in sourdough discard until combined. Add flour; beat to combine. Add chocolate; beat to combine. Let stand 30 minutes.
Preheat oven to 350°F. Use a 2-ounce scoop to form 1/4-cup balls of dough; arrange on parchment-lined baking sheets, spaced 2 inches apart. (Formed balls can be refrigerated in an airtight container up to 24 hours, or frozen up to 1 month; if making from frozen, add about 2 minutes to baking time.)
Bake 9 minutes. Remove sheets from oven and bang on a hard surface or oven rack. Bake 3 minutes more; remove and bang again. Bake until cookies begin to brown at edges and are just set in center, 3 to 5 minutes more. Let cool on sheets on a wire rack 5 minutes, then transfer directly to rack and let cool completely (or serve warm). Cookies can be stored in an air-tight container at room temperature up to 3 days.
