01 - Preheat oven to 350°F and line a 12-cup muffin tin with paper liners or lightly grease each cup.
02 - In a large bowl, whisk together the eggs, milk, protein powder, maple syrup, cinnamon, vanilla extract, and salt until smooth and well combined.
03 - Add bread cubes to the egg mixture, tossing gently until bread is well coated and has absorbed most of the liquid. Let sit for 5 minutes.
04 - Divide the soaked bread mixture evenly among the muffin cups, pressing down lightly to compact the mixture.
05 - Sprinkle your choice of toppings (nuts, chocolate chips, berries) over each muffin.
06 - Bake for 20 to 25 minutes, or until the muffins are puffed, golden brown, and set in the center.
07 - Let cool for a few minutes before removing from the tin. Serve warm or at room temperature.