Preheat oven to 350°F. Lightly grease four oven-safe glass meal prep containers.
Divide the cubed bread among the four containers.
In a mixing bowl, whisk egg whites, eggs, pumpkin, protein powder, milk, vanilla, pumpkin spice, maple syrup, and salt.
Pour evenly over each container, pressing lightly so all bread gets soaked.
Bake uncovered 28–32 minutes, until puffed and golden.
Cool, cover, and store in the fridge.
Serve with Greek yogurt, maple syrup, extra cinnamon, or pumpkin butter.