Start by cutting your French bread into 1-inch cubes. If the bread isn’t stale, spread the cubes out on a tray and leave them overnight. The drier the bread, the better it will absorb the custard, giving you a deliciously soft yet firm consistency.

Grease your baking dish lightly to prevent sticking. Spread the bread cubes evenly across the dish, then layer slices of ripe banana over the top. This step creates the irresistible banana flavor that anchors the entire dish.

Whisk together eggs, milk, heavy cream, brown sugar, vanilla extract, cinnamon, and a pinch of salt until fully combined. Pour this mixture over the bread and bananas, ensuring everything gets soaked. Use the back of a spoon to lightly press down the bread, so nothing remains dry.

Cover the baking dish tightly with plastic wrap and refrigerate it for at least 2 hours, ideally overnight. This allows the bread to absorb all the flavors and ensures a well-set casserole after baking.

When you’re ready to bake, preheat your oven to 350°F (175°C). Mix flour, brown sugar, and cubed butter with your fingers until crumbly to create the topping. Sprinkle this mix evenly over the casserole and bake for 45–55 minutes, or until the top turns golden and the custard is fully set.

Once out of the oven, serve the casserole warm. A drizzle of syrup, a dusting of powdered sugar, or a dollop of whipped cream can take it over the top.