Heat the milk in a small saucepan lukewarm, add the yeast and stir until it has dissolved.
Put flour, butter, sugar, salt and the egg in a mixing bowl. Add the yeast milk and mix with the dough hooks at slow speed. Then knead at the highest speed until the dough detaches from the bowl (about 8 minutes).
Cover the bowl with a cloth and leave the dough in a warm place for about 30 minutes.
Put approximately 450 ml of the milk in a saucepan and bring to a boil.
Mix the remaining milk in a bowl with the sugar and pudding powder.
Remove the boiling milk from the heat and stir in the mixed pudding powder with a whisk. Put it back on the stove and bring to a boil.
Set the pudding aside and let cool.
Put all ingredients in a bowl and knead to crumbles.
Roll out the dough rectangular on a floured work surface to the baking sheet size (30 x 40 cm). Lay out the baking tray with a piece of baking paper and place the rolled dough on top.
Put the pudding on the dough and spread evenly.
Finally, spread the crumbles on it and let the cake rest for another 15 minutes.
Then bake in a preheated oven at 200°C top/bottom heat for about 25-30 minutes. Remove and allow to cool.