Grease a 9 x 13 pan with nonstick cooking spray, set aside.
Add sausage to a large skillet and cook over medium high heat until fully cooked and no longer pink. Remove from the pan and set aside.
Add bell peppers, onions and mushrooms to the same pan and sauté until tender, 5-6 minutes.Add in spinach and cook until wilted, set aside.
Layer the bread in the prepared baking pan and top with sausage and bell pepper.
In a large bowl, whisk together eggs, cream and seasonings.
Pour egg mixture evenly over casserole. Sprinkle with cheese.Refrigerate overnight or bake immediately.
When your ready to eat preheat the oven to 350 degrees.Bake uncovered for 50-55 minutes or until the eggs look set.Serve immediately with green onions, if desired.