For the filled hazelnut cookies, mix the ingredients for the shortbread dough until smooth. Let the dough rest for at least 1/2 hour.
Then divide the dough into two halves and roll each out to a thickness of 2 mm. Cut out round circles from one part, and circles with a hole from the other. Place on a baking tray lined with baking paper and bake in a preheated oven at 160-170 °C until golden brown.
Let the cookies cool, assemble with jam and sprinkle with brittle and powdered sugar.