Defrost the dough sheets side by side. Halve each dough sheet crosswise and place it on two baking trays lined with baking paper. Prick the dough plates several times. Place two paper cups inside each other, fill them up to the rim with peas and place them in the middle of the dough plates.
Separate the egg. Whisk egg whites. Brush all dough corners with egg white and fold over once inwards up to the edge of the paper cups and press down lightly. Whisk egg yolk and 1 tbsp. water. Spread the edges of the dough and sprinkle with flaked almonds
Bake in the preheated oven (electric cooker: 200 °C/circulating air: 175 °C/gas: level 3) for 20-25 minutes. Take out the Copenhageners, remove the paper cups with the peas. Let the Copenhageners cool down
Mix cream cheese, sugar, vanillin sugar and cream with the whisk of the hand mixer. Wash the plums, dab dry, halve and stone them. Use a knife to cut in but not through the curvatures
Pour cream cheese cream into the middle of the particles. Place 2 plum halves on each. Heat the jam, pass it through a sieve and spread it on the pieces