Put flour and butter in food processor and pulse until mixture resembles small crumbs.

Add in the sugar and egg yolk and process until the mixture begins to form a dough. The dough will still be crumbly.

Knead dough on a lightly floured surface until it comes together and is smooth.

Wrap up in plastic wrap and refrigerate for 30 minutes.

Preheat oven to 350 degrees. Line two baking sheets with parchment paper or lightly grease.

Roll out dough on a lightly floured surface to 1/4 inch thickness.

Cut out cookies with cookie cutter. If you are doing cutouts, do half of the cookies whole, and half of them with a cutout.

Place on cookie sheet and bake for 10 minutes or just until you see a little color. Do not over bake!

Cool on a wire rack.

Combine marshmallow fluff and preserves in a small bowl.