Making Overnight Blueberry French Toast Casserole is simple when you follow these steps:

1. Prepare the Bread: Cut the French bread into cubes and place them in a large mixing bowl.
2. Add Blueberries: Gently fold in the blueberries, ensuring they are evenly distributed among the bread cubes.
3. Make the Custard: In another bowl, whisk together the eggs, milk, heavy cream, granulated sugar, vanilla extract, ground cinnamon, and salt until well blended.
4. Combine Mixtures: Pour the custard mixture over the bread and blueberries. Gently toss to coat all the bread pieces evenly.
5. Transfer to Baking Dish: Grease a 9×13-inch baking dish and pour the mixture into it, spreading it out evenly.
6. Chill Overnight: Cover the dish with plastic wrap and refrigerate overnight to allow the bread to soak up the custard.
7. Preheat the Oven: In the morning, preheat your oven to 350°F (175°C).
8. Add Butter: Drizzle the melted butter over the top of the casserole before baking.
9. Bake: Remove the plastic wrap and bake for 45-50 minutes, or until the top is golden brown and a knife inserted in the center comes out clean.
10. Cool Slightly: Allow the casserole to cool for about 10 minutes before serving.

With these simple steps, you’ll create a delicious breakfast casserole that your family will rave about!