Grease a 9×13 casserole dish with butter or nonstick spray.

Layer half the chopped Canadian bacon in the dish.

Toast and butter the English muffins, then chop into 1-inch pieces. Spread half over the bacon.

Repeat with the remaining bacon and muffin pieces.

In a large bowl, whisk eggs, cream, milk, salts, pepper, onion powder, paprika, and mustard powder until smooth.

Sprinkle optional shredded cheese over the casserole.

Pour the egg mixture evenly across the layers. Cover tightly with foil and refrigerate at least 4 hours or overnight.

Preheat oven to 375°F. Bake covered for 35 minutes, then uncover and bake 10–15 minutes more until the center is set (a knife should come out clean).

Make hollandaise: Blend egg yolks, cream, lemon juice, mustard, cayenne, and salt for 30 seconds. Slowly stream in melted butter until creamy.

Slice casserole into portions and serve warm with hollandaise drizzled on top.