Prep the oven and pans: Preheat to 350°F (175°C). Line two baking sheets with parchment paper.
Mix dry ingredients: In a bowl, whisk flour, baking soda, baking powder, and salt.
Set aside.
Infuse the sugar: In a large bowl, add sugar and lemon zest. Use your fingers to rub the zest into the sugar until it’s fragrant and slightly damp. This releases the oils for stronger flavor.
Cream the butter and sugar: Add softened butter to the lemon sugar.
Beat with a hand mixer or stand mixer on medium for 2–3 minutes, until light and fluffy.
Add wet ingredients: Beat in the egg, lemon juice, and vanilla (and lemon extract if using) until smooth. Scrape the bowl as needed.
Combine wet and dry: Add the dry ingredients in two additions. Mix on low just until no streaks of flour remain.
Don’t overmix.
Shape the cookies: Scoop 1 1/2-tablespoon mounds (about a heaping tablespoon). Roll each ball in the extra granulated sugar to coat.
Bake: Arrange 2 inches apart on the prepared sheets. Bake 9–11 minutes, until the edges are set and the centers look soft and slightly puffy.
They should not brown deeply.
Cool: Let cookies rest on the sheet for 5 minutes, then transfer to a rack to cool completely. They’ll finish setting as they cool.
Serve: Enjoy as-is or dust lightly with powdered sugar for extra sparkle.