Preheat the oven to 350°F. Grease a baking dish generously with butter or line with parchment paper.
In a saucepan over medium heat combine the milk, heavy cream, butter, sugar, salt, vanilla, cinnamon, and apple pie spice. Whisk gently until the butter is fully melted and everything is combined. Remove from heat.
Whisk the room temperature eggs together in a separate bowl. Slowly add a small amount of the warm custard to the eggs while whisking constantly. Continue adding the custard a little at a time until the eggs are fully tempered. Whisk the egg mixture back into the remaining custard.
Add the bread pieces to the custard and toss gently until completely coated. Let soak for a few minutes so the bread fully absorbs the custard.
Add a layer of custard-soaked bread to the prepared baking dish. Spoon a layer of apple pie filling over the bread. Add another layer of soaked bread then another layer of apple pie filling. Press down gently to compress the layers. Finish with apple pie filling over the top and a generous sprinkle of raw sugar.
Bake at 350°F for about 40 minutes until firm and set in the center and deeply golden on top.
Serve warm with vanilla ice cream.