Let’s bring this delicious dish to life with these easy steps:

1. Preheat your oven to 375°F (190°C). Grease a 9×13-inch baking dish with butter.
2. Spread the cubed English muffins evenly across the bottom of the prepared dish.
3. Sprinkle the diced Canadian bacon over the muffins, ensuring even distribution.
4. In a large bowl, whisk together the eggs, milk, onion powder, salt, pepper, and Dijon mustard until well combined.
5. Pour the egg mixture over the muffins and bacon, pressing down gently to ensure everything is soaked.
6. Cover the dish with aluminum foil and let it sit in the refrigerator for at least an hour, or overnight for best results.
7. When ready to bake, remove the foil and bake in the preheated oven for 35-40 minutes, until the eggs are set and the top is golden.
8. While the casserole is baking, prepare the Hollandaise sauce. Melt the butter in a saucepan over medium heat, then whisk in the flour to form a roux. Cook for about 1 minute.
9. Gradually whisk in the heavy cream, lemon juice, and cayenne pepper, cooking until the sauce has thickened, about 5 minutes.
10. Once the casserole is done, pour the Hollandaise sauce over the top and garnish with chopped parsley before serving.

Cooking is an art, and every dish tells a story. For me, this casserole is a testament to the joyful chaos of family meals, where everyone contributed a little magic to the table.