Place the puff pastry slices next to each other and defrost. Wash, halve and stone the plums. Cut marzipan into cubes. Sift 2 tbsp. icing sugar on top. Separate the egg. Add egg white and jam to the marzipan and mix to a smooth mixture with the whisk of the hand mixer.
Roast the almonds in a pan without fat, take them out. Place the puff pastry slices on top of each other and roll out (approx. 13 x 28 cm). Fold edges approx. 1 cm, press on and notch with a fork.
Whisk the egg yolk and milk, brush the edges with it. Spread strips with marzipan paste and cover with plum halves. Bake in the preheated oven (electric cooker: 225 °C/ convection oven: 200 °C/ gas: level 4) for 10-15 minutes, remove from oven.
Dust with 1-2 tablespoons icing sugar and sprinkle with chopped almonds.