Toast black sesame seeds for ~30 seconds until you can smell a toasted black sesame aroma. Pour into a spice grinder and pulse until it becomes very fine.
Mix the flour and powdered black sesame seeds together. Set aside.
Cream powdered sugar and butter until fluffy. Add in the vanilla extract and salt. Mix until well combined.
Sift the dry ingredients from step 2 into the wet ingredients. Combine with a spatula until a soft dough forms.
Roll out the dough onto a silicone mat until it is 1/4 an inch thick.
Transfer the silicone mat onto a baking sheet. Rest dough in the fridge for at least 30 minutes.
Move the oven rack to the center of the oven. Preheat oven to 350 degrees F.
Prepare 2 baking sheets by covering them with parchment paper.
After 30 minutes, take the dough out from the fridge. Use a cookie cutter that is 2.5 inches in diameter to cut out your cookies. After you cut out your first batch, combine the remaining dough, and roll it out to cut more cookies. Repeat this process until you run out of dough.
Place cookies onto the prepared baking sheets. Bake cookies for 9-11 minutes until the edges start to turn a golden color.
Cool cookies for 10 minutes.
Combine the ingredients for the glaze and drizzle onto the cookies.