Beat butter, sugar, and salt on medium speed for 3 to 4 minutes until pale and fluffy.

Mix in egg yolks and vanilla just until combined, scraping the bowl as needed.

Gradually add flour on low speed until a cohesive dough forms, adding extra flour if sticky.

Roll dough between parchment to an even ¼ inch thickness.

Cut 3 inch rounds and gently press edible flower petals onto each cookie.

Freeze cookies on a lined baking sheet for 12 to 24 hours.

Bake at 350°F for 9 minutes, rotate, then bake 8 more minutes until edges are lightly golden.

Cool on a wire rack and sprinkle with cane sugar while warm.