For the base melt butter, crumble biscuits finely. Mix crumbs and butter. Wrap the bottom edge of a springform pan (26 cm Ø) tightly with aluminium foil. Press the crumbs in the tin to a flat base.
Chill for about 30 minutes.
In the meantime, dice the marzipan for the cheese mixture. Mix with approx. 100 g cream cheese and sugar with the whisks of the mixer. Stir in the remaining cream cheese, crème fraîche and starch. Stir in the eggs one by one.
Preheat oven (electric cooker: 200 °C/circulating air: 175 °C/gas: see manufacturer). Put the cheese mixture on the crumb base and smooth it down. Place the mould in a fat pan (deep baking tray), push it onto the middle shelf and fill the fat pan with boiling water to a height of approx. 1 cm.
Bake in a hot oven for 45-50 minutes.
Remove from the oven and let it cool on a cake rack for about 1 hour. Then remove from the edge of the springform pan and take the cake out of the pan. Chill for about 1 hour.
Squeeze oranges, measure 150 ml of juice. Mix juice and jam sugar, bring to the boil and boil for approx. 4 minutes until bubbly, skimming off any foam. Let jam cool down until it is lukewarm.
Then stir vigorously and spread on the cake.