Preheat the oven to 350°F (175°C). Line two baking sheets with parchment paper.

In a stand mixer or large bowl with a hand mixer, cream the salted butter, granulated sugar, and lemon zest together until light and fluffy, about 2–3 minutes.

In a separate bowl, whisk the all-purpose flour and baking soda together until combined.

Add the egg to the creamed butter mixture and mix until incorporated.

Add the lemon juice and lemon extract to the butter mixture and mix until evenly combined.

Gradually add the flour mixture to the wet ingredients in 2–3 additions, mixing on low speed (or folding by hand) until the dough just comes together. Do not overmix.

Use a tablespoon to scoop portions of dough. Roll each portion between your palms to form neat balls.

Place the dough balls on the prepared baking sheets about 2 inches apart. Flatten each ball to about 1/4 inch thickness using the bottom of a glass or the back of a spoon.

Bake for 8–10 minutes, until the edges are light golden and the centers are still slightly soft.

Let the cookies cool on the baking sheet for 5 minutes, then transfer them to a wire rack to cool completely.