Place the granulated sugar, freeze-dried raspberries, salt and powdered sugar to the bowl of a food processor. Pulse just enough times to pulverize the raspberries -- it's ok to have a few small chunks left. Set aside.

In the bowl of a stand mixer, cream the butter for about a minute until smooth. Add in the sugar mixture and beat for another minute or until incorporated.

Add the egg yolk and vanilla; mix until combined. Add the flour slowly and mix until just incorporated.

Divide the dough in half. Roll each half into a log -- about 9 inches each. (See rolling tip in notes.) Refrigerate for about 2-3 hours or until firm.

When ready to bake, preheat the oven to 350. Prepare 2 baking pans by lining with parchment paper. Set aside.

Using a sharp knife, slice ¼ inch slices from the log and place them onto the prepared baking sheets.

Bake the cookies for about 18-20 minutes or until the edges begin to turn golden. Remove from oven and allow to cool completely.