01 - Preheat oven to 350°F and line two baking sheets with parchment paper.
02 - Whisk together flour, baking powder, and salt in a medium bowl.
03 - Combine lemon zest and dried lavender in a small bowl. Rub together gently with fingers to release essential oils.
04 - Beat softened butter and granulated sugar in a large bowl until light and fluffy, approximately 2–3 minutes.
05 - Add egg, vanilla extract, and lemon juice to butter mixture. Beat until fully incorporated.
06 - Stir in the lemon zest and lavender mixture until evenly distributed.
07 - Gradually add dry ingredients to wet mixture, mixing until just combined. Take care not to overmix.
08 - Scoop tablespoon-sized dough balls onto prepared baking sheets, leaving 2 inches of space between each.
09 - Bake for 10–12 minutes until edges are lightly golden.
10 - Allow cookies to rest on baking sheet for 5 minutes, then transfer to wire rack to cool completely.