Step 1Preheat the oven to 350°F and line a cookie sheet with parchment paper. Set aside.
Step 2In a small bowl combine the sugar and the lemon zest, using your fingers to rub the zest into the sugar until the sugar starts to clump together and is fragrant.
Step 3In a stand mixer fitted with the paddle attachment, combine the butter and the lemon sugar. Beat on medium speed, gradually increasing to high until the butter is light and fluffy, and pale in color; about 3 minutes.
Step 4Use a rubber spatula to scrape the down the sides of the bowl. Add the egg, egg yolk, lemon juice, and vanilla extract (and lemon extract if using). Beat until smooth and completely combined.
Step 5Scrape down the bowl and add the flour, baking powder, baking soda, and salt. Stir on low speed until combined and no streaks of flour remain. Do not over mix.
Step 6Fill one small bowl with granulated sugar and one bowl with powdered sugar. Use a 1.5 ounce cookie scoop to scoop cookies out. Roll the balls first in the granulated sugar and then in the powdered sugar to completely coat the cookie balls.
Step 7Place the cookies 2 inches apart on your cookie sheet. Bake for 10 to 12 minutes or until the edges are set and the centers have puffed up, but are still gooey. Remember, the cookies will continue to cook as they cool so you want them to be a little under baked when you take them out. Allow the cookies to cool completely.
