Start by measuring out your dry ingredients: all-purpose flour, baking powder, and salt. In a separate bowl, zest your fresh limes using a microplane, capturing the fragrant oils.

In a large mixing bowl, cream the softened unsalted butter and granulated sugar together using an electric mixer on medium speed for about 3-4 minutes until pale and fluffy.

Incorporate one large egg, lime juice, lime zest, and vanilla extract into the butter-sugar mixture. Mix on low speed until fully combined.

Gradually fold in the pre-measured dry ingredients with a spatula, being careful not to over-mix, until you have a cohesive dough.

Cover the dough with plastic wrap and chill in the refrigerator for about 15 minutes.

Preheat your oven to 350°F (175°C).

Scoop tablespoonfuls of dough onto parchment-lined baking sheets, spacing them about 2 inches apart. Bake for 10-12 minutes.

Once baked, let the cookies cool on the baking sheet for about 1 minute before transferring them to a wire rack to cool completely.