01 - Pulse the sugar and lilac blossoms in a food processor until flowers are finely chopped and sugar becomes fragrant with pale purple hue.
02 - Whisk together flour, baking powder, and salt in a medium bowl until evenly blended.
03 - Beat butter and prepared lilac sugar in a large bowl until mixture becomes light and fluffy.
04 - Add egg and vanilla extract to butter mixture, beating until fully incorporated.
05 - Gradually add dry ingredients to wet mixture, mixing just until flour disappears and dough forms.
06 - Divide dough in half, shape into discs, wrap in plastic, and refrigerate for at least 1 hour.
07 - Preheat oven to 350°F and line baking sheets with parchment paper.
08 - Roll dough on lightly floured surface to 1/4 inch thickness and cut into shapes using cookie cutters.
09 - Place cookies on prepared sheets and bake for 8 to 10 minutes until edges are just golden.
10 - Let cookies rest on pan for 5 minutes, then transfer to wire rack to cool completely.