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. Set aside.
03 - Beat the butter and sugar together in a large bowl until light and fluffy, about 2-3 minutes.
04 - Mix in the egg yolk, lemon zest, lemon juice, and vanilla extract until fully combined.
05 - Gradually add the dry ingredients to the wet mixture, mixing just until incorporated.
06 - Fold in the chopped lavender until evenly distributed throughout the dough.
07 - Scoop rounded tablespoons of dough and roll into balls. Place them 2 inches apart on the prepared baking sheets.
08 - Gently press your thumb or the back of a teaspoon into the center of each ball to create an indentation.
09 - Bake for 10 minutes. Remove from the oven and gently reinforce the indentation if needed.
10 - Fill each indentation with about 1/2 teaspoon of lemon curd.
11 - Return cookies to the oven and bake for an additional 2 minutes, or until the edges are very lightly golden.
12 - Cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.