For the bread pudding: Preheat the oven to 350 degrees. Prepare the bottom and sides of the baking dish with the butter.
In a large bowl, add the croissant and bread chunks along with the chocolate chips sprinkled over the top. Toss gently and pour into the prepared dish making sure all the chocolate chips don't settle on the bottom.
In a large bowl, whisk together the milk, chocolate syrup, brown sugar, cinnamon, salt, nutmeg and eggs. Pour the chocolate custard over the bread in the baking dish and press the bread down into the custard to soak it up. Allow to rest for 10 minutes. Then press down a bit again.
For the topping: In a medium bowl, toss the butter and with the flour to coat all sides of the butter. Then add the pecans, brown sugar, salt and cinnamon. Mix together with your hands to get the butter to blend into all the ingredients. Sprinkle evenly over the top of the baking dish.
Bake uncovered until the edges are golden brown and the center springs back a bit when touched, 45 to 50 minutes. Allow it to cool and settle for about 30 minutes and then make pretty squares, or just dig in right away. Serve with a dollop of Bourbon Whipped Cream. Can also be served cold.
Bourbon Whipped Cream:
In a large bowl, whisk heavy cream until soft peaks form. Add the bourbon and sugar and continue to whisk until stiff peaks form when the whisk is removed from the bowl. Refrigerate and serve cold.