01 - Preheat oven to 350°F. Line baking sheets with parchment paper.
02 - Whisk together flour, baking powder, and salt in a medium bowl until evenly blended.
03 - Lightly crush dried lavender with lemon zest using a mortar and pestle or spice grinder to release essential oils. Set aside.
04 - Beat softened butter and granulated sugar in a large bowl until light and fluffy, approximately 2 minutes.
05 - Mix in egg, vanilla extract, and lemon juice until thoroughly combined.
06 - Fold in the crushed lavender-lemon zest mixture until evenly distributed.
07 - Gradually add dry ingredients to wet mixture, mixing just until flour disappears. Do not overmix.
08 - Scoop tablespoon-sized dough balls onto prepared baking sheets, leaving 2 inches of space between each.
09 - Bake for 10 to 12 minutes until edges are lightly golden.
10 - Let cookies rest on baking sheet for 2 minutes, then transfer to wire rack to cool completely.