Can be prepared and refrigerated the night before serving. Remove from refrigerator 30 minutes before baking.
Preheat oven to 350 degrees
Spray 9X13 inch pan with nonstick cooking spray
In large mixing bowl, beat eggs
Add cheeses and stir to combine
Stir in spinach
Pour into prepared casserole dish (or put into 8 small custard cups)
Bake 45 minutes to 1 hour or until eggs are cooked through
Cool slightly before cutting into square servings