For the short pastry, knead flour, cold fat in flakes, icing sugar, salt and egg to a smooth dough. Wrap in foil and put in the fridge for about 30 minutes. Knead dough briefly and roll out thinly on a floured work surface.
Cut out hearts with two different sized moulds and place them on 2-3 baking trays lined with baking paper. Whisk the egg yolks and whipped cream. Brush the smaller hearts with it. Bake the cookies one after the other in a preheated oven (electric: 200 °C/ gas: level 3) for 10-12 minutes.
Let it cool down. Finely chop the walnuts. Mix nuts, sugar, butter, orange fruit and cream in a pot and bring to the boil. Let simmer for about 2 minutes while stirring. Spread the mixture into the middle of the big hearts.
Cover each with a small heart. Allow to set and dust with icing sugar.