In a large mixing bowl, combine the softened butter and granulated sugar. Use an electric mixer to cream them together until light and fluffy (3-5 minutes).
Add the vanilla sugar and the egg, mixing until well incorporated.
In a separate bowl, whisk together the all-purpose flour, almond flour, and salt. Gradually add this mixture to the wet ingredients, mixing until just combined.
Form the dough into a disc, wrap it in plastic wrap, and refrigerate for at least 1 hour.
Preheat your oven to 180°C (350°F). Roll out the chilled dough to about ¼ inch thick and use cookie cutters to cut out shapes.
Place the cookies on a baking sheet lined with parchment paper and bake for 10-12 minutes until the edges are lightly golden.
Once cooled, spread a layer of apricot or cranberry jam on the solid cookies and gently place the cut-out cookies on top. Dust with powdered sugar.