Cream butter with sugar - Add softened butter and granulated sugar to a stand mixer bowl. Beat with the paddle attachment for at least 2 minutes until well incorporated and creamy.
113 grams unsalted butter, 150 grams granulated sugar
Incorporate sourdough starter - Add the egg yolk, vanilla extract, almond extract, lemon juice, sourdough starter and continue beating for at least another 2 minutes until fluffy and creamy.
1 large egg yolk, 5 grams pure vanilla extract, 3 grams almond extract, 5 grams lemon juice, 60 grams sourdough starter discard
Add dry ingredients - Sift flour and baking soda directly into the wet ingredient mixture in the stand mixer bowl, sprinkle salt on top, stir until incorporated. Stop the mixer and scrape down the sides and bottom of the bowl as necessary.
180 grams all-purpose flour, 3 grams baking soda, 2 grams kosher salt
Scoop and chill - Portion the cookie dough with a 1 ½-tablespoon cookie scoop and place them on a lined baking sheet. Roll into balls. Cover and refrigerate while the oven preheats. You don’t need a long chill for this dough.
Preheat the oven to 350°F.
Bake - Roll the dough balls in granulated sugar, place 12 on a half sheet baking sheet, and bake for about 13 minutes, until the edges of the cookies start to turn lightly golden.
25 grams granulated sugar
Cool - Remove the baking sheet from the oven, and allow the cookies to sit on the baking sheet to finish baking from the residual heat for 10-15 minutes before removing them to a wire rack to cool completely.