Sieve the flour into a bowl and make a well in the middle.
Now add the butter, 50 g powdered sugar, the seeds from the vanilla pod, the lemon zest and the egg to the well. Then knead everything together with your hands until you have a smooth dough.
Cover the dough and place in the fridge for an hour.
Then preheat the oven to 170°C.
Roll out the dough - approx. 1 cm thick - and then cut out.
Place the cookies on a baking tray lined with baking paper and spread the center with lemon jam.
Bake in the middle of the oven for 10 minutes.
After baking, dust with the remaining powdered sugar.