Preheat the oven to 350°F (175°C). Butter a 9x9 inch baking dish.
Cut the French bread into cubes and place them in the prepared dish.
In a mixing bowl, whisk together milk, granulated sugar, eggs, vanilla extract, and ground cinnamon until combined.
Pour the custard mixture evenly over the bread cubes, pressing them down gently to soak. Let it sit for 10 minutes.
Bake in the preheated oven for 40-45 minutes or until the top is golden brown and the custard is set.
While baking, make the caramel sauce: melt butter in a saucepan over medium heat, add brown sugar and cook until bubbly. Stir in heavy cream and simmer for 3-4 minutes until thickened.
Remove bread pudding from oven, let cool slightly, then drizzle with warm caramel sauce before serving.
Notes
Best served warm with a scoop of vanilla ice cream for extra indulgence.