Preheat your oven to 350°F (175°C).

In a large bowl, cream the softened butter and granulated sugar together until light and fluffy.

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

In a separate bowl, whisk together the flour, baking powder, and salt. Gradually add this mixture into the butter mixture, mixing just until combined.

Gently fold in the fresh blackberries without crushing them.

Using a cookie scoop or a tablespoon, drop the dough onto a lined baking sheet, leaving space between each cookie.

Bake in the preheated oven for 12-15 minutes or until the edges are golden.

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