Mix flour, sugar, orange peel and salt in a mixing bowl. Add butter in flakes and the egg. Knead first with the dough hooks of the hand mixer, then with cool hands to a smooth dough. Wrap the dough in cling film and chill for about 30 minutes. Briefly knead the dough until it is smooth and roll out to a thickness of approx. 4 mm on a well floured work surface. Cut out hearts with a heart cutter (approx. 5.5 cm Ø).
Place hearts on 2 baking trays lined with baking paper. Spread almond flakes on the cookies and press them lightly. Bake the baking trays one after the other in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for about 12 minutes. Take out, place on a grid and let cool off. Dust the cookies with icing sugar
Waiting time approx. 1 hour