Cinnamon Roll French Toast Casserole with Brioche Bread

Grease a baking dish (9x9 square pan or 11x7 rectangle pan. Larger pans will work, but the bake time might be reduced). Preheat oven to 350 degrees if baking same day.
To make the egg mixture, combine the eggs, milk, vanilla extract and cinnamon together in a large bowl. Whish together and set aside.
To make the cinnamon sugar filling , add the brown sugar, cinnamon and softened butter together in a medium bowl. Mix together until fully combined.
Taking one slice of of brioche bread, spread a generous layer of the cinnamon sugar mixture onto the slice. Top with second slice of bread, creating a sandwich. Repeat until all the bread has been used.
Cut the cinnamon sugar sandwiches into bite sized pieces and place into the greased baking dish. Pour the egg mixture over the bread and carefully toss to coat all the bread pieces. Cover and place in the fridge for at least 15 minutes and up to 8 hours.
When ready to bake, remove cover and bake at 350 degrees for 40-50 minutes or until the internal temperature reaches at least 160 degrees F and the egg custard has fully set. The bread should have puffed up.
While the French toast casserole is baking, make the cream cheese frosting by adding the cream cheese and softened butter together in a large bowl. Beat together until smooth. Add in the powdered sugar and vanilla extract. Beat together until smooth.
Once the cinnamon roll French toast is done, remove from oven and spread the cream cheese frosting over the top of the casserole. Enjoy!