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