For the sauce:

1. In a heavy medium saucepan bring cream, whiskey, maple syrup, and vanilla seeds (throw the half pod in to simmer with the sauce) to low boil over medium-high heat, stirring frequently. Keep your eye on this, it can boil over quickly, then you’ve got a fine mess on your hands! Reduce to simmer. Mix cornstarch and 2 teaspoons water in small bowl to blend; whisk into cream mixture. Simmer until sauce thickens, stirring constantly, about 3 minutes. Strain the sauce to remove the vanilla pod and any bits of coagulated cream) Cool, then cover and refrigerate until cold, at least 2 hours. (May be made 4 days ahead. Keep refrigerated.)
   

For the bread pudding:

1. Preheat oven to 350°F. Coat a 13 x 9 x 2-inch glass baking dish (or make this in two pretty casserole dishes, whatever works!) with butter or non-stick spray.
2. Combine cubed bread, chocolate, and white chocolate in large bowl; toss to blend together. In another large bowl, whisk eggs, 1/2 cup brown sugar, and vanilla to blend. Gradually beat in 1-1/2 cups half and half and milk. Add half and half mixture to bread and chocolate; stir to combine. Let sit at room temp. for at least 30 minutes.
3. Transfer bread mixture to prepared dish, spreading evenly. Drizzle with remaining half & half mixture. Sprinkle with remaining 2 tablespoons brown sugar. Cover with foil and bake pudding until custard is set in center, about 50 minutes, remove foil and bake another 10 minutes until edges are golden. Cool pudding slightly.
4. Cut into serving sizes and drizzle bread pudding with chilled sauce serve warm.