Preheat your oven to 375°F (190°C) and line a baking sheet with parchment paper.

In a mixing bowl, whisk together the flour, baking powder, and salt.

In another bowl, cream together the softened butter and granulated sugar until light and fluffy. Beat in the egg and vanilla extract.

Gradually add the dry ingredients to the wet ingredients, alternating with sour cream, until well combined.

Gently fold in the fresh blueberries into the cookie dough.

Use a spoon to drop dough onto the prepared baking sheet, leaving space between each cookie.

Bake for 12-15 minutes or until the edges of the cookies are lightly golden.

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