Knead 250 g flour, fat in pieces, 60 g sweetness, 1 egg and salt to a smooth dough. Cover and chill for about 1 hour
Roll out the dough on a lightly floured work surface to a thickness of approx. 3 mm. cut out 40 large (approx. 5 x 5 cm) and 40 small hearts (approx. 4 x 4 cm)
Place hearts on 2-3 baking trays lined with baking paper. Whisk egg yolk and 1-2 tbsp. water. Brush small hearts with it. Bake all hearts in the preheated oven (electric cooker: 200 °C/recirculating air: 175 °C/ gas: level 3) for 8-10 minutes. Let them cool down
Warm the jam. Finely chop the nuts and stir into the jam. Put about 1/4 teaspoon on each of the big hearts. Place small hearts on top. Let cool down. Sprinkle with 3 g sweetness