Cream the butter. Add the sugar, salt and vanilla sugar, beat briefly. Stir in the egg white. Gradually add the flour and almonds, mix by hand to form a dough, flatten a little, cover and refrigerate for at least 2 hrs.
To shape, divide the dough into quarters. Roll it out in portions between a cut-open plastic bag to a thickness of approx. 4 mm. Loosen the dough with a spatula, cut out hearts (approx. 7 cm), place on two baking trays lined with baking paper. Cut the middle out of half of the biscuits using a smaller heart-shaped cutter (approx. 4 1/2 cm). Coat the open hearts with a little egg yolk and scatter with flaked almonds. Leave the trays to chill for approx. 15 mins.
Bake each tray for approx. 8 mins. in the centre of an oven preheated to 200°C. Remove from the oven, allow to cool on a cooling rack. Dust the open hearts with a little icing sugar.
Combine the jam and raspberry schnapps, spoon onto the middle of the hearts (without almonds), cover each one with an open heart.