Carve peaches crosswise. Scald with boiling water, rinse cold and peel off skin. Cut peaches in half, stone them.
Cream fat, sugar and salt with the whisk of the hand mixer. Stir in the eggs one after the other. Mix flour and baking powder, alternating with the yoghurt. Grease the fat pan of the oven and dust with flour. Put half of the dough into the pan and smooth it down. Stir the poppy seed mixture into the other half, pour it onto the light-coloured dough and smooth it down.
Place the peaches on the dough with the cut surface facing down. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for 35-45 minutes. Warm up the jam. 10 minutes before the end of the baking time, brush the cake with the jam. Leave to cool on a cake rack. Dust with icing sugar.