For the Mauserln first prepare the choux pastry. To do this, bring the milk, salt, butter and sugar to the boil, pour in the flour and stir the dough until it is smooth and separates from the vessel.
Once the mixture has cooled a bit, stir in the beaten eggs in small batches, stirring the dough in between every now and then until smooth.
Before use, let the dough rest for half an hour, then put it in a piping bag, pipe mousses onto a baking sheet and bake in the oven first at 220 degrees for 10 minutes and then at 200 degrees for another 5-10 minutes.
For the cream, mix the pudding powder, sugar and egg with a little milk until smooth, bring the remaining milk to the boil, stir in the pudding, allow to cool slightly, stir in the cooking chocolate and rum.
Let the finished mousse cool down a bit, cut in the middle and fill with the custard.