In a large mixing bowl, whisk together the eggs, milk, granulated sugar, cinnamon, and 1 teaspoon vanilla extract until smooth.
Add the bread cubes to the bowl and toss gently until the liquid is absorbed.
Melt 2 tablespoons of butter in a large non-stick skillet over medium heat.
Place half of the bread cubes in the skillet in a single layer and cook for 5 to 7 minutes, turning frequently until golden brown on all sides.
Transfer the cooked bites to a plate and repeat the process with the remaining butter and bread cubes.
In a small bowl, whisk the powdered sugar, heavy cream, and remaining vanilla extract until a smooth glaze forms.
Drizzle the glaze over the warm french toast bites and serve immediately.