Preheat the oven to 450F degrees.
In a bowl, whisk together the eggs, cream, salt, pepper, garlic powder, onion powder, and red pepper flakes. Set aside.
In a medium cast iron skillet, heat the butter on medium heat. Add the ground breakfast sausage. Use a spoon to break up the sausage, and cook until browned and slightly crispy.
Add the spinach. It should cook down quickly.
Place one half of the shredded cheese over the sausage and spinach mixture.
Immediately pour the egg mixture into the skillet. Place skillet in preheated oven.
Remove the skillet from the oven after 6 minutes, and sprinkle the remaining cheese over the frittata.
Slice frittata and serve!