Preheat oven to 350-degrees.
Melt the butter in a large skillet over medium heat. Add the minced shallots and saute for approximately 1 minute.
Add the spinach to the skillet. Stir well. Cover and cook for 3 minutes.
Add the chopped red peppers to the skillet. Stir well. Cover and cook for 3 minutes.
In a medium bowl, whisk together the eggs, cream cheese, cottage cheese, heavy cream, Parmesan, mozzarella, salt, pepper, nutmeg and garlic powder.
Turn off the heat. Carefully pour the egg mixture into the spinach mixture and stir well to combine.
Pour the spinach and egg mixture into a prepared 3-quart casserole dish that has been liberally sprayed with cooking spray.
Place the casserole dish on a baking sheet and place into a preheated 350-degree oven until the center is set, and the casserole is golden brown, approximately 60 minutes.
Remove the casserole from the oven to cool slightly before serving.