Preheat the oven to 375 degrees.
Grease a 13 x 9 baking dish and set aside.
Cut up your choice of bread into bite-size pieces and place them in the greased baking pan.
If you are adding mix-ins, you can sprinkle them on top of the bread pieces.
Add the milk, eggs, vanilla, a dash of salt and cinnamon to taste. Whisk together.
Pour the liquid over the bread pieces in the pan.
Top the pan with a piece of foil to prevent over-browning.
Put the pan in the oven and bake for 45 minutes.
Remove foil from the pan and bake for 10-15 more minutes.
Remove from the oven an allow the casserole to rest for 5 minutes before serving with toppings.