01 - Preheat the oven to 350°F. Line two baking sheets with parchment paper.
02 - Whisk together the flour, baking powder, and salt in a medium bowl.
03 - Combine the lavender and lemon zest in a small bowl. Rub them together with your fingers to release the oils and fragrance.
04 - Beat the butter and sugar together until light and fluffy, about 2-3 minutes.
05 - Beat in the egg, then add the vanilla extract and lemon juice, mixing until combined.
06 - Stir in the lavender-lemon zest mixture until evenly distributed.
07 - Gradually add the dry ingredients to the wet mixture, mixing just until combined. Do not overmix.
08 - Scoop tablespoon-sized portions of dough onto the prepared baking sheets, spacing them about 2 inches apart.
09 - Bake for 10-12 minutes, or until the edges are just beginning to turn golden.
10 - Let the cookies cool on the baking sheets for 5 minutes, then transfer to a wire rack to cool completely. Dust lightly with powdered sugar if desired.