Begin by tearing your day-old bread into bite-sized pieces and place them in a greased baking dish. In a separate bowl, whisk together eggs, milk, heavy cream, sugar, vanilla extract, and ground cinnamon until smooth. Pour this mixture over the bread, cover, and refrigerate overnight.

On the day of your brunch, preheat your oven to 350°F (175°C). Remove the casserole from the refrigerator and let it sit at room temperature for about 15 minutes.

In a small bowl, combine brown sugar, chopped nuts if desired, and melted unsalted butter. Sprinkle this mixture over the top of the casserole before baking.

Place the dish in the preheated oven and bake for 45 to 50 minutes, until the edges are golden brown.

Remove the casserole from the oven and allow it to cool for about 10 minutes before slicing. Serve warm, optionally topped with fresh fruit or powdered sugar.

If you have leftovers, allow to cool completely before storing in the fridge for up to three days.