Sourdough Vanilla Wafers

Preheat the oven to 350ºF (177ºC) and line a couple of sheet pans or cookie sheets with parchment paper.
Beat the softened butter and sugar in the bowl of a stand mixer fitted with the paddle attachment (or a hand mixer) for a few minutes until pale and fluffy.
113 g Unsalted Butter, 100 g Granulated Sugar
Add the wet ingredients and mix until combined.
1 Egg, 50 g Sourdough Discard, 1 TBS Vanilla Extract
Mix the dry ingredients in a small bowl. Then, pour into the stand mixer bowl, pulse a few times so the flour doesn't spill, and mix just until combined.
At this point, you can chill the batter up to a couple of days in the refrigerator to make ahead.
180 g All-purpose flour, ½ tsp Kosher Salt, ½ tsp Baking powder
Use a small spoon or measuring spoon to scoop 1 ½ tsp of batter, roll between the palms of your hands, and place two inches apart on the prepared baking sheets. If the dough is sticky, chill for 15-30 minutes.
Use dampened fingers with water to gently press down on the cookies to thin circles to help them spread.
Bake for 13-15 minutes, or until the edges start to brown and the bottoms are dark brown. They will continue to crisp as they cool.