Preheat oven to 350. In a large mixing bowl whisk together eggs, cream, and milk until well combined. Add in sugar cinnamon vanilla and splash of butter until everything is well blended(you can smell heaven). Now you have to get messy, break up all of the bread into the custard and fold together by hand until all of the bread is soaked(you will have some excess liquid but its ok) and let sit for about 20 minutes. Melt the the 1 stick of butter and pour the melted butter in a 13 x 9 baking dish. Pour the bread pudding into the dish and bake for 50-60 minutes in which i prefer 60 but your oven is different but the sides should form a nice brown crust.
For the sauce,slightly melt white chocolate chips in a bowl in microwave and set aside. In a saucepan melt 1 stick butter on medium heat until it starts to slightly bubble, add in bourbon, cream and powdered sugar and whisk while still on heat until well combined and then add melted white chocolate chips and continue to whisk, if too thick add more cream.
I say start the sauce 20 minutes before you pull the bread pudding out of the oven and if you decide not to use the white chocolate chips in the sauce then substitute 1 cup of granulated sugar for the powdered sugar and add more bourbon.