These egg muffins are delicious and NOT the least bit dry or spongy thanks to the use of stale bread. They make breakfast meal prep easy and are great to grab and go during a busy week.
Set the cubed bread out the night before to get stale. Alternatively, spread bread over a baking sheet and bake at 225 for 10 minutes to dry. Let cool completely.
Whisk eggs, milk, garlic and onion powder, salt and pepper well to combine. Dice the bell pepper and roughly chop the spinach.
Grease 2 12-cup muffin tins well with cooking spray. Distribute bread cubes evenly over the 24 muffin cups. Repeat with the bell pepper and spinach. Using a ladle, pour the egg and milk mixture evenly and carefully in the muffin cups.
Set the muffins in the refrigerator for at least an hour, up to overnight.
Preheat the oven to 350 and remove muffins from the fridge. Top each muffin with grated cheddar and bake for 18-20 minutes until just set. Let cool completely before removing. Use a knife to run along the edges of the muffins if necessary.
Storing: Wrap two at a time tightly in plastic wrap then place in a large ziploc bag in the freezer for easy grab and go breakfasts all week. Reheat in the microwave for 1-2 minutes.