Start by melting your butter over medium heat in a saucepan. Use a pan with a light-colored bottom so you can keep track of the color while the butter starts to brown. Swirl the pan occasionally to make sure that the butter is cooking evenly. As the butter melts, it will begin to foam, sputter and the coloring will get darker. Once the butter has developed a deep golden brown color and has stopped sputtering, pour into a heatproof glass container and set aside.
½ Cup Butter
Gather the dry ingredients: flour, baking powder, baking soda, and salt. Place these dry ingredients in a medium bowl and whisk them together to ensure they are well combined.
3 cups + 2 Tablespoons All-purpose flour, 1 teaspoon Baking powder, 1 teaspoon Baking soda, 1 teaspoon Kosher salt
In a separate large bowl, combine the browned butter and sugars. Use a stand mixer with a paddle attachment or a hand mixer to mix the ingredients for a few minutes.
1 cup Granulated sugar, 1 cup Brown sugar
Add the egg yolks and continue to mix for a few minutes on medium speed.
3 Egg yolks
Mix the sourdough starter and vanilla into the mixture for a few minutes until the mixture becomes smooth and combined
1 cup Sourdough starter discard, 2 teaspoon Vanilla extract
In two parts, add the flour mixture to the batter. Mix on low speed just until everything comes together to form a dough, being careful not to overmix.
Add the chocolate chips to the dough. Mix gently with a spatula until the chocolate chips are evenly incorporated throughout the dough.
2 ⅔ Cups Dark chocolate chips
Cover the cookie dough with plastic wrap or move the dough into an air tight container. Set in the fridge for at least 2 hours so that the dough starts to solidify before baking.
Preheat your oven to 350F. Meanwhile, with a 3 tablespoon cookie scoop, scoop the dough into uniform dough balls and place on a prepared baking sheet lined with parchment.
Bake for about 15-18 minutes or until you notice that the edges are set and slightly golden brown. If you notice that the cookies are spreading too much for your liking, you may need to chill the dough a bit longer!
Remove the cookies from the oven, sprinkle with flakey salt and after about 4 minutes, transfer them to cooling rack before enjoying!
Flakey sea salt