Grease a 9x13 baking dish with butter or cooking spray.
In the baking dish, arrange the English muffins, cut sides up, slightly overlapping each other.
Place a Canadian bacon slice in between each English muffin. Set aside.
In a separate bowl whisk together eggs, milk, garlic powder, onion powder, paprika, and nutmeg.
Pour the egg mixture over the top of the English muffins; press down on the English muffins so that they are mostly covered with the egg mixture. It's okay if they're not all the way under.Cover the casserole dish with plastic wrap and aluminum foil, and refrigerate overnight, or for at least 4 hours.
Preheat oven to 375˚F.
Remove plastic cover and recover with foil.
Bake for 30 minutes.
Remove foil and continue to bake for 25 to 30 more minutes, or until casserole is set and tops of the muffins are lightly browned.
Remove from oven.
Let stand 10 minutes.
Serve with Hollandaise sauce.
Nutritional Facts do not include the Hollandaise Sauce.