Step-by-Step Instructions

• Brown the Butter. Start by adding your unsalted butter to a small saucepan over medium heat. Let it melt down, stirring often. After a few minutes, it’ll foam and begin to smell nutty. The milk solids will toast at the bottom of the pan—once they turn golden and the butter deepens in color, remove from heat. Let it cool for about 10 minutes.
  1 Cup Unsalted Butter
• This step adds a rich, toasted flavor you just can’t get from regular melted butter—but if you’re short on time, you can swap in plain melted butter.
• In a large mixing bowl, stir together the cooled brown butter, brown sugar, and white sugar. Add the egg yolks , vanilla, and sourdough starter discard. Mix well with a wooden spoon or hand mixer if you prefer.
  1 Cup Dark Brown Sugar, 2/3 Cup White Sugar, 2/3 Cup Sourdough Starter Discard, 2 Large Egg Yolks, 2 Teaspoons Pure Vanilla Extract
• Add the Dry Ingredients. In a separate bowl, combine the flour, baking soda, baking powder and salt. Add this mixture into the wet ingredients and stir until just combined. Fold in your chocolate chips, chocolate chunks, or whatever chocolate you have on hand. This dough smells good enough to eat raw (but we recommend baking it).
  2 ¾ Cups All-Purpose Flour, 1 Teaspoon Baking Soda, 1 Teaspoon Baking Powder, 1/2 Teaspoon Salt, 1 ½ Cups Dark Chocolate Chips
• Chill the Dough, optional. If you’ve got the time, let the dough rest in the fridge for 30 minutes (covered with plastic wrap or in a bowl with a lid). This helps the flavors develop and makes for a chewier texture and less spread while baking.
• Bake. Preheat the oven to 350°F. Line your cookie sheet or baking tray with parchment paper or reuse a parchment-lined baking sheet if you’re baking multiple batches.
• Use a cookie scoop or tablespoon to portion out the dough. Leave room between the cookies—they’ll spread. Bake for about 10–12 minutes, until the edges are golden brown and the centers are still soft.
• Cool for a few minutes on the tray, then transfer to a cooling rack or wire rack to finish setting up. Sprinkle with flaky sea salt if you wish.
  Optional: a sprinkle of flaky sea salt for the tops of the cookies