In a large bowl, cream together softened butter and granulated sugar until light and fluffy.

Beat in the egg yolk and vanilla extract until well combined.

Gradually add the all-purpose flour and mix until a soft dough forms.

Divide the dough into two equal portions, flatten each into a disk, and wrap in plastic wrap.

Chill the dough for at least 30 minutes in the refrigerator.

On a lightly floured surface, roll out one disk of dough to about 1/8-inch thickness.

Using a fluted round cookie cutter, cut out 10 circles from the rolled dough.

From 5 of these circles, use a smaller cutter to make a small hole in the center.

Place the cookies on a baking sheet lined with parchment paper and bake at 350°F (175°C) for 10-12 minutes, or until lightly golden at the edges.

Once cooled, spread about 1 teaspoon of raspberry jam onto each whole cookie.

Dust the cookies with holes with powdered sugar.

Carefully place a sugared cookie top onto a jam-covered cookie bottom to form a sandwich.