Mix flour, baking powder and salt and sieve onto a work surface. Press a depression in the middle. Place the eggs and lemon peel in the depression. Sprinkle sugar on the rim. Spread fat in flakes on the rim.
Knead everything into a smooth shortcrust pastry. Cover and put in a cool place for about 30 minutes. Grease a baking tray (27x27 cm). Roll out the shortcrust pastry evenly on the baking tray and press the edge up a little.
Prick the bottom several times with a fork. Bake in the preheated oven (electric oven: 200°C/ gas: level 3) for approx. 25 minutes and let cool off. Stir pudding powder, 60 g sugar and approx. 1/8 litre milk until smooth.
Bring the remaining milk to the boil, stir in the pudding powder and bring to the boil again briefly. Let cool for 5-10 minutes. Spread the pudding on the cake. Pluck the grapes from the stems, wash and drain well.
Halve the grapes, remove the seeds and spread on the pudding. Mix the cake glaze and the remaining sugar in a saucepan, stir in the grape juice bit by bit. Bring to the boil while stirring. Pour the icing evenly over the grapes.
Allow to set for about 1 hour. Roast the flaked almonds in a dry pan until golden brown. Sprinkle over the cake just before serving. Results in about 20 pieces.