Using a stand mixer fitted with the paddle attachment, beat the softened butter and granulated sugar for about 3 minutes (or until creamed/light & fluffy), scraping down the sides of the bowl as needed.
1 ½ cups granulated sugar, 12 tbsp unsalted butter, softened
Add in the egg, egg yolk, milk, and vanilla. Scrape down sides again as needed.
1 large egg, room temperature, 1 large egg yolk, room temperature, 1 Tbsp. whole milk, 2 tsp. vanilla extract
In a separate bowl, whisk together dry ingredients.
3 cups all-purpose flour, spooned and leveled, 1 ½ tsp. baking powder, ¾ tsp. salt, ½ tsp. baking soda
Gradually add them in at a slow speed just until combined.
Chill the dough for 30 minutes or overnight. If you feel the cookie dough is dry, see recipe notes below.
When ready to bake, preheat the oven to 325°F. And line baking sheets with parchment.
Remove the cookie dough from the fridge. If very cold, allow to sit on the counter for ~10 minutes so it's easier to scoop and roll.
Add about ¼ cup granulated sugar into a bowl for rolling.
granulated sugar, for rolling and garnishing
Scoop and roll the cookie dough into about 1 ½ tbsp.-sized balls.
Roll the cookie dough balls in the granulated sugar. Repeat with remaining cookie dough.
Bake for ~8-10 minutes, being very careful not to over bake.
Cool on the cookie sheet just for a few minutes then transfer to wire rack to cool completely. Garnish with a sprinkle of granulated sugar. Enjoy!
Store on the counter in an airtight container for 3-4 days or freeze for up to 3 months.