01 - Pulse granulated sugar and lilac blossoms in a food processor until flowers are finely chopped and sugar becomes fragrant with pale purple tint. Set aside for immediate use.
02 - Whisk together all-purpose flour, baking powder, and salt in a medium bowl until thoroughly blended.
03 - Beat room temperature butter and prepared lilac sugar in a large bowl until mixture appears light and fluffy, approximately 2-3 minutes.
04 - Incorporate egg and vanilla extract into butter mixture, beating until fully combined and smooth.
05 - Gradually add dry ingredients to wet mixture, mixing until just incorporated. Avoid overmixing to maintain tender texture.
06 - Divide dough in half, shape into discs, wrap tightly in plastic wrap, and refrigerate for minimum 1 hour to firm.
07 - Preheat oven to 350°F and line baking sheets with parchment paper.
08 - Roll chilled dough on lightly floured surface to 1/4 inch thickness. Cut into desired shapes using cookie cutters.
09 - Arrange cut cookies on prepared baking sheets. Bake for 8-10 minutes until edges turn lightly golden.
10 - Let cookies rest on baking pan for 5 minutes, then transfer to wire rack to cool completely before serving.