Preheat your oven to 350°F (175°C).

Line a baking sheet with parchment paper.

In a large bowl, cream together the softened butter and granulated sugar until light and fluffy. Add the egg, lemon juice, and lemon zest, mixing until well combined.

In another bowl, whisk together the flour, baking powder, baking soda, and salt. Gradually add this dry mixture to the wet ingredients, mixing until just combined.

Gently fold in the fresh blueberries.

Using a spoon or cookie scoop, drop rounded tablespoons of the dough onto the prepared baking sheet, leaving space between each cookie.

Bake in the preheated oven for 10-12 minutes, or until the edges are golden brown.

Remove from the oven and allow to cool on the baking sheet for 5 minutes before transferring to a wire rack.