Pour egg mixture over the bread cubes and combine well.TIP: Using gloves is the best way to distribute the mixture without breaking up the cubes. Gently toss bread in the mixture several times.
Brush 1 tablespoon of the melted butter all over the bottom and sides of the baking dish. Add the bread cube mixture to the pan. Cover with plastic wrap and allow to sit at room temperature for one hour, or in the fridge up to overnight.
When ready to bake, preheat oven to 400 F.
Combine remaining 1/2 tablespoon of the cinnamon, remaining 1 1/2 tablespoons of the brown sugar and 1 tablespoon of melted butter. Distribute all over the top of the casserole.
Bake uncovered for 25 minutes or until top is golden brown and a toothpick poked in the center comes out clean.
Allow to cool for 5-10 minutes before cutting and serving.
Thicker, sturdier breads such as Italian bread, French bread, brioche, Texas toast, or challah are all great options as they are hearty enough to not become soggy from the filling. I've found that stale bread works best for this as it's begun to dry out, which allows it to soak up the egg mixture better.