Our Gabled Home

0 In a large mixing bowl, combine flour, sugar, and vanilla sugar. Add the butter in small chunks, grated lemon zest (if using) and the egg. Mix well with an electric mixer. Use your hands to make the dough come together. 
1 Shape the dough into logs, wrap them in plastic and chill the dough logs for 60 minutes in the refrigerator. 
4 Preheat the oven to 400˚F (200˚C).
2 With a rolling pin, roll the dough evenly thin (about 3mm thick). Cut out half of the dough in medium-sized shapes. Cut out the same shapes from the rest of the dough but punch small holes or smaller shapes from the middle. 
3 Transfer the cookies to a cookie sheet and bake in the preheated oven for 8-10 minutes. 
5 Let the cookies cool down for a few minutes before transferring them to a wire rack. 
6 Once cooled, spread a thin layer of jam on each whole cookie and press a cut-out cookie shape on top. Dust the finished cookies with powdered sugar.