Preheat oven to 400 °F (200 °C).
Cut the rolls or brioche into cubes.
Peel and core the apples and cut into slices.
Mix the bread, apples, and almonds.
Beat the cream, eggs, and sugar and fold into the bread mixture.
Flavor with cinnamon and Calvados.
Fill a buttered dish and bake for about 30 minutes.
For the elderberry sauce, boil the red wine, elderberries, sugar, and cinnamon and simmer for 15 minutes.
Sieve.
Mix a bit of cornstarch with a little bit of water and then stir into the simmering sauce.
Remove the apple casserole from the dish and serve with the elderberry sauce and powdered sugar.
