For the domino hearts, knead flour with sugar, butter in pieces, egg, honey, baking soda, hazelnuts and spice until smooth and let rest in a cool place for about 1 hour.
Roll out dough on a floured work surface to about ½ cm thick and cut out hearts with a ramekin and place on a baking tray lined with baking paper. Bake in preheated oven at 200°C for about 8-10 minutes.
Allow to cool. In the meantime, warm the marmalade with a dash of rum and brush the hearts thinly with it. Knead marzipan with powdered sugar.
Roll out the mixture thinly between 2 layers of cling film. Also cut out hearts with the same form and lay on the cookies.
Melt the dark chocolate coating on a hot water bath. Coat the hearts with it and then let dry. Melt the white chocolate coating as well. Fill into a small freezer bag, cut off a corner and decorate the domino hearts as desired.