Preheat oven to 350°. Line several rimmed baking sheets with parchment paper.
In a medium bowl, beat together butter and sugar with a mixer at medium speed until creamy, 3 to 4 minutes, stopping to scrape sides of bowl. Add egg yolk, rose water, and vanilla bean paste beating until well combined. Add flour, salt, and candied rose petals, beating until a dough forms.
Using a rolling pin roll out dough to a ¼-inch thickness on a lightly floured surface. Using a 1½-inch fluted round cutter cut 30 cookies from dough, rerolling scraps as necessary. Place on prepared baking sheets.
Bake until cookies are set, 8 to 10 minutes. Let cool on pans for 5 minutes. Remove from pans, and let cool completely on wire racks. Store at room temperature in an airtight container for up to 2 days.
Just before serving, garnish with rose petals, if desired.
Recipe by TeaTime Magazine at https://teatimemagazine.com/rose-thins/