Preheat your oven to 375°F (190°C) and coat a 9x13-inch baking dish with non-stick spray. Layer half of the Canadian bacon across the bottom.

Add half of the English muffin pieces on top of the bacon, covering the bottom evenly.

Layer the remaining Canadian bacon on top, followed by the rest of the English muffin pieces.

In a mixing bowl, whisk together the eggs, whole milk, onion powder, salt, garlic powder, and black pepper until fully combined.

Pour the egg mixture evenly over the layers in the baking dish. Cover tightly with plastic wrap and refrigerate for at least 2 hours.

Remove the plastic wrap, sprinkle paprika on top, then bake for 35-40 minutes until firm and golden.

Let the casserole rest for a few minutes, then drizzle with warmed hollandaise sauce and garnish with parsley.