01 - Whisk together flour, baking powder, and salt in a medium bowl. Set aside for later use.
02 - Beat softened butter, granulated sugar, and brown sugar in a large bowl until light and fluffy, approximately 2-3 minutes.
03 - Incorporate eggs one at a time, mixing well after each addition. Blend in vanilla extract and lemon zest if desired.
04 - Lightly mash half the blueberries with lemon juice in a small bowl, maintaining some whole fruit pieces for texture.
05 - Stir the mashed blueberry mixture into the wet ingredients until evenly distributed.
06 - Gradually fold the dry ingredients into the wet mixture, mixing until just combined. Avoid overworking the dough.
07 - Gently fold in the remaining whole blueberries, distributing them evenly throughout the dough.
08 - Cover the dough and refrigerate for a minimum of 1 hour until firm enough to handle.
09 - Preheat oven to 350°F. Line two baking sheets with parchment paper for easy cleanup.
10 - Scoop approximately 1.5 tablespoons of dough and roll into balls. Coat each ball generously in powdered sugar until completely covered.
11 - Place sugar-coated dough balls 2 inches apart on prepared baking sheets to allow for spreading.
12 - Bake for 11-13 minutes until edges are set and tops show characteristic crinkle patterns. Centers should remain slightly soft.
13 - Let cookies rest on baking sheets for 5 minutes, then transfer to a wire rack to cool completely before storing or serving.