For the Burgenländer, quickly knead the flour with the finely chopped butter, sugar and egg yolk into a smooth dough. Shape into a ball and place in the refrigerator wrapped in foil for about 30 minutes.
Preheat the oven to 160°C top and bottom heat.
Roll out the dough on a floured work surface to a thickness of approx. 3 mm and cut out circles of approx. 5 cm (smaller if desired). Place on a baking tray lined with baking paper.
Beat the egg whites with the sugar until stiff, fill into a piping bag with a star-shaped nozzle and pipe a ring of small dots onto the outer edge of the cookies. Bake in the preheated oven for about 12 minutes until golden brown. Remove and let cool.
Heat the jam with the lemon juice, strain through a sieve, fill into the center of the Burgenländer (with a piping bag or spoon) and let dry.