Preheat the oven to 325°F and spray an 8x8 inch square baking dish with cooking spray. Place the cubed french bread into a large mixing bowl.
In a separate medium size mixing bowl whisk together the milk, eggs, granulated sugar, brown sugar, vanilla and cinnamon.
Pour over the cubed bread. Mix together then pour the mixture into the prepared dish.
In a small bowl use a fork to mix together the melted butter, granulated sugar, brown sugar and cinnamon. Sprinkle evenly on top.
Place into the oven and bake for 45-55 minutes or just until the top is golden and the center is set. Test with the tip of a knife inserted into the center, it should come back clean.
Rest for 5 minutes on the counter before serving dusted with powdered sugar.
Notes
To top this cinnamon bun bread pudding with a vanilla cream glaze:In a small bowl whisk together 1 cup of powdered sugar with ½ teaspoon vanilla extract and enough heavy cream or milk to thin. Start with one tablespoon at a time and mix, repeating until your desired consistency is reached. Drizzle on each piece of bread pudding just before serving.