01 - Pulse granulated sugar and fresh lilac blossoms in a food processor until flowers are finely chopped and sugar becomes fragrant with pale purple hue. Set aside for later use.
02 - Whisk together all-purpose flour, baking powder, and salt in a medium bowl until uniformly blended.
03 - Beat room-temperature unsalted 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 blend dry ingredients into wet mixture, mixing only until just incorporated. Avoid overmixing to prevent tough cookies.
06 - Divide dough in half and shape into discs. Wrap securely in plastic wrap and refrigerate for minimum 1 hour to firm for rolling.
07 - Preheat oven to 350°F. Line baking sheets with parchment paper and set aside.
08 - Roll chilled dough on lightly floured surface to 1/4 inch thickness. Cut shapes using cookie cutters of choice.
09 - Arrange cut cookies on prepared baking sheets. Bake 8-10 minutes until edges turn just golden. Centers should remain slightly soft.
10 - Let cookies rest on baking sheet for 5 minutes before transferring to wire rack. Cool completely before serving or storing.