Whisk eggs in a large bowl. Add milk, cream, sugar, vanilla, and cinnamon. Whisk together until frothy.
Tear croissants into bite size pieces - about the size of a quarter. Add to liquid mixture and stir gently until croissant pieces are soaked. Add sliced apples and stir to combine.
Pour mixture into a buttered 9x13 pan and allow to soak overnight.
Tightly cover pan with foil and bake for 60 minutes.
Remove covering and test doneness by inserting a knife in the center of the pudding. If knife does not come out clean, recover and bake for 5 minute increments until the center shows no liquid custard.
Remove from oven and allow to set for 5-10 minutes before serving.
For the Caramel Sauce:
While bread pudding is baking prepare the caramel sauce.
Combine 1/2 cup whipping cream, sugar, corn syrup, and butter in a heavy, medium-sized sauce pan.
Over medium-high heat, bring to a boil until it turns a light caramel color (about 6-10 minutes), stirring constantly (keep an eye on it, it will foam up near the end and you may need to reduce the heat).
Remove from heat and add remaining 1 cup whipping cream. It's ok if the caramel clumps up a little as you pour the cream in, keep stirring and it will smooth out.
Keep sauce warm and serve over bread pudding. Top with whipped cream and serve.