Pre heat oven to 350F. Line a muffin tin with cupcake liners or grease the cups
Spread the peanut butter and jelly between slices of bread making 4 sandwiches. Cut into 1' cubes.
Divide the cubed PB&J pieces evenly among the 12 muffin cups filling them close to the top
In a large mixing bowl, whisk together eggs, milk, maple syrup, vanilla, cinnamon and salt (and protein powder if using it)
Pour evenly our each muffin cup, pressing lightly so the bread soaks up the liquid. Let the muffins sit for 5 minute before baking
Bake for 20-25 minutes until puffed and golden and the custard is sent in the center
Let cool for 5 minutes before removing from the muffin tin
Serve warm with a drizzle of maple syrup or powdered sugar