Brown the butter. In a saucepan, melt butter over medium-low heat. Increase heat to medium and cook, stirring constantly. Butter will sizzle and pop. Once popping slows or stops and you notice the butter is beginning to turn golden brown (there will be brown flecks on the bottom of your pan) immediately remove from heat. Pour into a large heatproof mixing bowl and allow to cool until no longer warm to the touch before proceeding.

Once butter has cooled, add sugars, eggs yolks, and vanilla extract and stir until well-combined.

Add sourdough discard and mix well, until fully incorporated.

In a separate bowl, whisk together the all-purpose flour, baking powder, baking soda, and salt.

Gradually add the dry ingredients to the wet, stirring until thoroughly combined.

Use a spatula to fold in chopped chocolate until well incorporated.

Cover with plastic wrap and chill for at least 30-60 minutes (or, my preference, overnight).

Once dough is ready to bake, preheat oven to 350F (175C) and line a baking sheet with parchment paper.

Scoop chilled dough into 1 ½ Tablespoon-sized balls, for neat, uniform cookies roll between your palms to make them round. Place on prepared baking sheet, spacing cookies at least 2 inches apart.

Bake for 10-12 minutes, until edges are beginning to turn golden brown (centers will still be soft and may appear slightly underdone).

Within several minutes of removing cookies from oven, sprinkle all over with flaky sea salt.

Allow cookies to cool completely on baking sheet before removing and enjoying.