Separate eggs. Beat the egg whites until stiff, allowing the sugar to trickle in. Beat the egg yolks until fluffy and fold into the beaten egg white. Mix flour, starch and baking powder, sieve over the egg mixture and fold in.
Pour foam mixture into a springform pan (26 cm Ø) lined with baking paper and bake in a preheated oven (electric range: 175 °C/ gas: level 2) for 30-35 minutes. For the cream mix gelatine with 4 tablespoons of cold water.
Drain the mandarins in a sieve, collecting the juice. Mix 125 ml tangerine juice with sour cream, vanilla sugar and sugar. Dissolve the gelatine, stir into the sour cream, then fold in the mandarins.
Heat 1 tablespoon of oil. Fry the remaining onion. Deglaze with wine and lemon juice, simmer briefly. Add cream. Bring to the boil and thicken. Season to taste
Dissolve gelatine and stir in. Leave to set in the refrigerator. When the cream mixture is firm, use an ice-cream scoop to cut off balls and place them on the firm sour cream. Serve dusted with coffee powder.
Results in about 12 pieces.