Brown bacon in a medium non-stick skillet over medium heat, using a wooden spoon to ensure even browning. Cook until bacon is browned, about 7-9 minutes. Strain on to a plate lined with a paper towel. Remove all but 2 tablespoons of the bacon grease from the pan then add in spinach. Saute until spinach is wilted, about 3-4 minutes.
While bacon and spinach are cooking, whisk eggs, water, salt and pepper in a large bowl. Add cooked, strained bacon and cooked spinach to the egg mixture and mix well. Pour mixture into prepared baking dish.
Sprinkle pan with shredded cheese then bake until eggs are set, about 30 minutes. Serve warm or refrigerate for up to 7 days.