01 - Preheat the oven to 350°F. Line two baking sheets with parchment paper.
02 - In a medium bowl, whisk together the flour, baking powder, and salt; set aside.
03 - In a large bowl, beat the butter and granulated sugar together until light and fluffy, about 2–3 minutes.
04 - Add eggs one at a time, mixing well after each addition. Beat in lemon zest, lemon juice, and vanilla extract until smooth.
05 - Gradually add the dry ingredients to the wet mixture, mixing just until combined.
06 - Gently fold in the blueberries with a spatula, taking care not to crush them.
07 - Scoop tablespoon-sized portions of dough and roll into balls. Roll each ball in powdered sugar to coat generously.
08 - Place the coated dough balls onto the prepared baking sheets, spacing them about 2 inches apart.
09 - Bake for 11–13 minutes, or until the cookies are set at the edges but still soft in the center.
10 - Allow cookies to cool on the baking sheets for 5 minutes before transferring to a wire rack to cool completely.