Prepare the Bake:Preheat oven to 350°F (175°C).Grease a 9x13-inch baking dish. Spread the cubed English muffins and diced Canadian bacon evenly in the dish.
Mix the Custard:In a large bowl, whisk together eggs, milk, salt, pepper, and Dijon mustard. Pour this mixture over the English muffins and bacon. Let it sit for 5 minutes to soak.
Bake:Cover the dish with aluminum foil and bake for 30 minutes. Remove the foil, drizzle melted butter over the top, and bake for another 15 minutes until golden brown.
Make the Hollandaise Sauce:In a blender, combine egg yolks, lemon juice, and cayenne pepper. Blend for 20 seconds. Slowly drizzle in melted butter while blending until thick and creamy. Season with salt.
Serve:Drizzle the hollandaise sauce over the baked casserole. Garnish with chopped parsley if desired and serve warm.
Notes
Make the hollandaise sauce just before serving to ensure it stays fresh and warm.