Rinse fresh blueberries under cool water, pat dry, and set aside. Preheat oven to 350°F (175°C) and line a baking sheet with parchment paper.

In a large mixing bowl, beat together the butter, light brown sugar, and granulated sugar until light and fluffy.

Add vanilla essence, lemon juice, and egg to the butter and sugar mixture. Beat until well combined.

Gradually add flour, baking soda, salt, and lemon peel to the wet mixture. Stir gently until combined.

Fold the blueberries into the cookie dough gently to avoid breaking them.

Portion about 1.5 tablespoons of dough per cookie onto the prepared baking sheet.

Bake cookies for 8-11 minutes, until edges are lightly browned and centers are slightly underbaked.

Cool cookies on the baking sheet for 10 minutes before transferring to a wire rack to cool completely.