In a large bowl, knead the flour, butter, powdered sugar, egg, egg yolk, salt, lemon zest, and vanilla sugar together to form a smooth shortcrust pastry.

Wrap the pastry in plastic wrap and chill it in the refrigerator for about 30 minutes.

After chilling, roll out the pastry to about 3 mm thick on a floured surface.

Using a cookie cutter, cut out cookies and place them on a baking sheet lined with baking paper.

Cut out an equal number of cookies with a hole in the middle using a smaller cookie cutter, and place them on a separate baking sheet.

Preheat your oven to 160°C (325°F) with the convection setting.

Bake the cookies until they are light golden brown, taking care not to overbake. Allow them to cool completely.

Dust the cookies with holes with a little powdered sugar for a sweet touch.

Spread a smooth layer of redcurrant jelly or apricot jam on top of the cookies without holes.

Carefully place the powdered sugar-dusted cookies on top of the jam-covered ones. Allow them to dry to ensure they stick together.