Cut rolls into slices, mix eggs with milk, powdered sugar and salt and soak the roll slices in it until they have absorbed the whole.
Peel apples and cut into thin slices.
Butter a gratin dish and spread the bottom with bun slices, form a layer of apple slices on top, sprinkle with some raisins and a mixture of cinnamon and granulated sugar, then repeat a layer of bun slices…continue until everything is used up together. The top layer should be bun slices.
Spread butter in flakes evenly on the surface and bake the pyre in the oven at 180 °C for 40-50 min.