Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

In a bowl, whisk together the flour, baking soda, and salt until well combined.

In a separate large bowl, cream the room temperature butter and granulated sugar together until light and fluffy, about 2-3 minutes.

Beat in the egg, followed by the key lime juice and lime zest, mixing until fully incorporated.

Gradually combine the flour mixture with the creamed mixture, stirring gently until just mixed.

Using a tablespoon or cookie scoop, drop rounded tablespoons of dough on the prepared baking sheet, leaving space for them to spread.

Bake for 10-12 minutes, or until the edges are lightly golden; the centers may still look soft but will firm up as they cool.

Allow the cookies to cool on the baking sheet for about 5 minutes before transferring them to a wire rack to cool completely.

For the glaze, mix powdered sugar with key lime juice until smooth.

Drizzle it over the cooled cookies and garnish with additional lime zest.