Preheat the oven to 180 °C top and bottom heat. Grease an ovenproof dish with butter.
Cut the stale yeast plait or white bread into slices about 1 cm thick.
Wash the currant, remove from the panicles and drain.
Layer the plaited pastry or bread slices in the form of roof tiles and spread the berries in between.
Mix the whipped cream with the milk, eggs and sugar and pour over the slices of braid or bread. Sprinkle everything with brown sugar, sprinkle the almond flakes on top and bake the bread casserole in the oven for 35-40 minutes.
Meanwhile, for the vanilla sauce, slit the vanilla bean lengthwise.
In a saucepan, bring the milk to a boil with the vanilla bean. Remove the pod and scrape the pulp back into the hot milk. Beat the egg yolks with the sugar until creamy. Gradually stir in the hot vanilla milk.
Transfer the mixture to a saucepan and heat, stirring, until the sauce thickens (but it must not boil!). Strain the custard through a fine sieve and allow to cool briefly, if desired.
Remove the Ofenschlupfer, sprinkle with powdered sugar and serve warm or cold.