Boil 1/4 litre of water, fat and salt. Add the flour at once and stir until the dough comes off the bottom of the pot as a lump. Pour the dough into a bowl. Stir in 1 egg immediately, the remaining eggs one after the other.
Chill the dough. For the filling, wash the plums, halve, stone and cut into slices. Sprinkle with 100 g sugar and leave to stand for about 30 minutes. Pour the choux pastry into a piping bag with a large star-shaped spout.
Spray 12 rectangles (approx. 4 x 6 cm) onto a baking tray lined with baking paper. Bake in a preheated oven (electric: 200 °C/ gas: level 3) for 25-30 minutes. Immediately after baking, cut through horizontally once and let cool down.
Steam the plums for about 5 minutes, remove with a skimmer. Let the stock boil down thickly and add the plums again. Soak gelatine in cold water. Mix yoghurt, sugar and lemon juice.
Dissolve gelatine at low heat, stir into the yoghurt and chill. Whip the cream until stiff as soon as the yoghurt begins to gel. Pour the yoghurt cream into a piping bag with a large star-shaped spout and squirt onto the lower halves of the dough, spread the compote on top.
Place the pastry lid on top and dust with icing sugar.