Cut the croissants in half and peel and slice the apples into VERY thin slices - so thin you can almost see through!
Arrange half of the croissants over the base of a 20cm square oven safe dish. Place the apple slices and ¼ cup of currants over the top and sprinkle with 1 tablespoon of the caster sugar.
Pour half of the custard over the top of the mixture.
Place the remaining croissants on top of the dish and pour over the remaining custard. Let the mixture sit at room temperature for 1 ½ hours to allow the custard to soak into the croissants.
Preheat your oven to 170 degrees.
Sprinkle the remaining currants and flaked almonds over the top of the soaked croissants and sprinkle with the remaining tablespoon of caster sugar.
Place the dish into your preheated oven and bake for one hour or until the top of the pudding begins to turn golden.
Carefully remove the pudding from the oven and let it sit for 10 minutes before cutting to serve.