Mix the dough and roll out on a lightly floured work surface or between 2 layers of cling film approx. 3 mm thick. Cut out 6 circles (approx. 8 cm Ø). Carefully place on a baking tray lined with baking paper.
Cut out small cookies (e.g. hearts and circles etc.) from the remaining dough and place them on a second baking tray lined with baking paper. Mix 1 egg yolk and 1 tablespoon of water. Brush the cookies with it.
Mix marzipan, icing sugar and the remaining egg yolks to a smooth mixture. Pour into a piping bag with star-shaped spout. Spray a wreath from the marzipan mixture onto the edges of the large cookies.
Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for 10-15 minutes. Remove and let cool on a cake rack. Bake the remaining cookies in 10-12 minutes.
Let it cool down on a cake rack and fill it in a well closed tin. Wash the grapes, dab dry, cut in half and remove the seeds. Drain the mandarins. Cover cakelets with fruit.
Heat the jam. Glaze the grapes and mandarins with it. Leave to dry. Serve with whipped cream.