Preheat the oven to 375 degrees, and grease a medium ceramic or glass baking dish, such as Pyrex.
Into the baking dish, add the eggs, milk, butter, cinnamon, vanilla, and salt. Beat the eggs with a fork until all ingredients are combined.
Place the bread pieces into the baking dish and fold into the egg mixture. Continue folding in the bread until all the egg mixture is absorbed. You might need to add an extra piece of bread if there is a lot of egg not being absorbed.
In a small bowl, combine the brown sugar and cinnamon for the topping (see below).
Evenly sprinkle the topping onto the egg and bread mixture.
Place the cinnamon toast mixture into the oven and bake for 25-30 minutes.