01 - In a medium mixing bowl, whisk together eggs, whole milk, granulated sugar, vanilla extract, ground cinnamon, and a pinch of salt until thoroughly combined.
02 - Add bread cubes to the custard mixture and gently fold to coat each piece. Let soak for 2 to 3 minutes so the bread absorbs the mixture without becoming soggy.
03 - In a shallow dish, thoroughly blend brown sugar and ground cinnamon to form the coating; set aside.
04 - Melt 1 tablespoon of unsalted butter in a large nonstick skillet over medium heat. Arrange half the soaked bread cubes in a single layer and cook, turning as needed, until all surfaces are golden and crisp, approximately 5 minutes.
05 - Wipe skillet if necessary. Melt the remaining tablespoon of butter, add the rest of the soaked bread cubes, and cook until browned and crisp.
06 - Immediately transfer hot French toast bites to the prepared cinnamon sugar dish and toss gently until evenly coated.
07 - Serve the cinnamon brown sugar French toast bites warm, optionally accompanied by maple syrup or fresh fruit.