Preheat the oven to 350°F. Grease a muffin tin with butter or cooking spray.
On a baking sheet, arrange the cubed bread and bake for 3-4 minutes until slightly dried out. (This is an important step to ensure the muffins do not become soggy when the liquid is added).
In a large bowl, whisk together the eggs, milk, cinnamon, sugar and vanilla extract.
Add the (lightly toasted) cubed bread to the bowl and fold until combined and bread has absorbed the liquid.
Divide the bread mixture among the muffin tin cups, pressing it lightly into each cup to compact it.
Bake French toast cups for 25 to 30 minutes until slightly crisp on top and cooked throughout.
Allow the cups to cool for 5 minutes in the muffin tin then scoop each one out and serve topped with maple syrup or vanilla glaze.
To make Vanilla Glaze:
Mix together 1 cup Confectioner’s Sugar, 1 teaspoon vanilla extract, and 2 tablespoons milk.