Preheat the oven to 350°F (175°C). Grease a muffin tin with butter or cooking spray.
In a large bowl, whisk together eggs, milk, cinnamon, sugar, and vanilla extract.
Add the cubed bread to the bowl. Fold until the bread absorbs all the liquid.
Divide the bread mixture evenly among the muffin tin cups. Press lightly to compact the mixture.
Bake for 25-30 minutes until the tops are crisp and cooked through. Let them cool for 5 minutes in the tin.
Remove from the muffin tin and serve warm with maple syrup or vanilla glaze.