Preheat your oven to 375°F (190°C). Line two large baking sheets with parchment paper.

In a medium bowl, whisk together the all-purpose flour, baking soda, and salt. Set aside.

In a large mixing bowl, cream together the softened unsalted butter and granulated sugar with an electric mixer on medium speed until light and fluffy, about 2-3 minutes.

Beat in the egg, vanilla extract, lemon zest, and lemon juice until well combined.

Gradually add the dry ingredients to the wet ingredients, mixing on low speed until just combined. Be careful not to overmix.

Gently fold in the fresh blueberries using a rubber spatula. Avoid overmixing to prevent the blueberries from breaking too much.

Drop rounded tablespoons of cookie dough onto the prepared baking sheets, leaving about 2 inches between each cookie.

Bake for 10-12 minutes, or until the edges are lightly golden and the centers are just set. The cookies may still look slightly soft in the middle.

Remove the baking sheets from the oven and let the cookies cool on the sheets for 5 minutes before transferring them to a wire rack to cool completely.

While the cookies are cooling, prepare the lemon glaze. In a small bowl, whisk together the powdered sugar and 2 tablespoons of fresh lemon juice until smooth. If the glaze is too thick, add more lemon juice 1/2 teaspoon at a time until it reaches a drizzly consistency.

Once the cookies are completely cooled, drizzle the lemon glaze over them using a spoon or fork.

Allow the glaze to set for about 15-20 minutes before serving.