Preheat your oven to 350 degrees F. This is essential for ensuring your cookies bake evenly. While the oven is heating, line two baking sheets with parchment paper or silicone baking mats. This will prevent the cookies from sticking and make cleanup a breeze.
In a small bowl, combine all-purpose flour, baking soda, baking powder, and salt. Whisk them together until well blended, then set the bowl aside. This mixture forms the dry ingredients that will give structure to your cookies.
Next, take another small bowl and combine granulated sugar and lemon zest. Rub the zest into the sugar with your fingers until fragrant. This step releases the essential oils from the lemon, infusing the sugar with a bright citrus aroma.
In a large mixing bowl, cream together unsalted butter and the lemon-infused sugar mixture using an electric mixer. Beat until the mixture is smooth and creamy, about 2 to 3 minutes. You'll know it's ready when it's light in color and fluffy.
Add in the egg, lemon juice, and a bit of vanilla extract. Mix until everything is well combined. The addition of lemon juice enhances the flavor of the cookies, making them irresistibly zesty.
Gradually add the dry ingredients to the wet mixture, mixing just until combined. Be careful not to overmix, as this can lead to tough cookies. The dough should be soft and slightly sticky.
Using a tablespoon, scoop rounded balls of dough and roll them in granulated sugar for that perfect sugary coating. Place the dough balls on the prepared baking sheets, ensuring they’re about 1.5 inches apart to allow for spreading.
Pop the cookies into the preheated oven and bake for 8 to 10 minutes. You’ll know they’re done when the edges are slightly brown and the cookies are set but still soft in the center.
Once out of the oven, let the cookies sit on the baking sheets for 2 minutes before transferring them to a cooling rack. This resting time allows them to firm up a bit while still warm.