Heat oven to 350°F; butter 9-by-13-inch dish. Toast muffin pieces on sheet 8 minutes; put in dish with Canadian bacon.
Whisk whole eggs, milk, salt, and black pepper; pour over filling. Soak 15 minutes.
Bake 30 to 35 minutes to 165°F in center. Rest 10 minutes while making sauce.
Whisk pasteurized yolks, water, and lemon juice in heatproof bowl above barely simmering water, without touching water. Whisk 3 to 5 minutes until thick enough to briefly trail.
Remove from heat; slowly whisk in warm melted butter, then cayenne. Spoon hollandaise over cut portions; serve immediately. Keep sauce out of oven.