01 - Preheat the oven to 350°F. Lightly grease a standard 12-cup muffin tin with butter or nonstick spray.
02 - Distribute the bread cubes evenly among the muffin cavities, filling each about three-quarters full.
03 - In a large mixing bowl, vigorously whisk together eggs, whole milk, heavy cream, granulated sugar, vanilla extract, ground cinnamon, and salt until the mixture is smooth and fully combined.
04 - Pour the custard mixture evenly over the bread cubes in the muffin tin, pressing the bread gently to ensure thorough absorption of liquid.
05 - Allow the muffin tin to stand at room temperature for 10 minutes, permitting the bread to fully soak up the custard.
06 - Top each filled muffin cup with fresh berries, if desired.
07 - Bake in the preheated oven for 25 minutes or until the tops are golden brown and the centers are set.
08 - Transfer the muffin tin to a wire rack and allow to cool for five minutes before gently removing the French toast cups.
09 - Serve warm, dusted with powdered sugar and drizzled with maple syrup as desired.