Wash the apples and cut out the core with an apple corer. Cut or slice apples into approx. 3 mm thick rings. Put them into a large pot. 1⁄2 Add l water, sugar and lemon juice and bring to the boil. Simmer at low heat for about 2 minutes. Take the puff pastry out of the fridge for 5-10 minutes. When the apple rings are soft and pliable, drain them, then drain them on kitchen paper and let them cool down.
Preheat oven (electric cooker: 200 °C/circulating air: 180 °C/gas: see manufacturer). Grease eight wells of a muffin tray (twelve wells). Unroll the puff pastry on the paper and cut it lengthwise into 8 strips (each approx. 2.5 cm wide) and into a 4 cm wide strip using a wavy pastry wheel. Form or cut out 8-12 leaves from the 4 cm wide strip of puff pastry and put aside.
Grate marzipan. Season sour cream with nutmeg. Spread the remaining strips thinly with the sour cream and sprinkle with marzipan. Cut apple rings in half, place them on the strips and roll them up. Press 1-2 pastry sheets on each side of the apple roses and then place them in the muffin tray. Bake in a hot oven for about 30 minutes until golden brown.
Take out the muffin tin and let the apple florets cool down in the tin. Remove from the mould. Warm up the jam in a small pot while stirring, possibly passing it through a sieve. Spread the apple florets with it. Dust with icing sugar before serving.