Preheat the oven to 350°F (175°C) and grease a muffin tin.
In a large bowl, whisk together eggs, milk, granulated sugar, vanilla extract, cinnamon, and salt.
Add the bread cubes and toss to coat evenly.
Divide the mixture evenly among the muffin cups.
In a separate bowl, mix melted butter, brown sugar, and cinnamon. Spoon over each muffin.
Bake for 20-25 minutes or until golden brown and firm to the touch.
Let cool for a few minutes before removing from the pan.
Dust with powdered sugar before serving, if desired.