Dice the bacon in small bits, cook and strain on paper towels.
Whisk the eggs and water in a bowl
Place defrosted spinach in a kitchen towel and squeeze out all the water
Mix the spinach, bacon, cheese, and mushrooms in the bowl along with the eggs, salt and pepper to taste
Place cupcake liners in a muffin pan, spray the cupcake liners with non stick spray, and fill each cupcake liner with the egg mixture
Bake 20-25 mins, or until center is firm.