Best Sourdough Discard Chocolate Chip Cookies

In a stand mixer fitted with a paddle attachment, beat unsalted butter, white sugar, and brown sugar on medium speed for 3 to 4 minutes until light and fluffy.
Add egg yolks, mixing on low speed until combined. Stir in sourdough starter discard and pure vanilla extract.
The mixture should resemble thick cookie batter.
In a medium bowl, whisk together all purpose flour, baking powder, baking soda, and the amount of salt listed.
Slowly add the dry ingredients to the wet ingredients in three additions, mixing just until combined.
Fold in milk chocolate chips until evenly distributed
Cover the large mixing bowl tightly with plastic wrap and refrigerate for at least 24 hours. (You can also shape the cookie dough balls and refrigerate that way.)
Preheat oven to 350 degrees.
Use a cookie scoop to form cookie dough balls. Place them on a parchment-lined baking sheet, leaving space between each.
Bake 12 to 14 minutes until edges are golden brown but centers still look slightly underdone.
For crisp edges and chewy centers, remove when the bottom of the pan shows light browning.
Let cool on the cookie sheet for 5 minutes, then transfer to a wire rack.
Optional: Add a sprinkle of flaky sea salt while warm.