Mix egg yolks and egg with sugar and sour cream or crème fraiche. Gradually add the flour and work into a smooth dough.
Roll out the dough as thinly as possible on a floured surface and prick a few times with a fork. Cut out rectangles of 10 x 5 cm with a baking wheel.
Heat the oil to 180 °C and bake the dough pieces in it for 3-4 minutes until done, then drain on kitchen paper.
Mix the cinnamon and powdered sugar, place in a sieve and dust the shards with it on both sides.