01 - Preheat oven to 375°F. Grease a 9x13-inch baking dish with butter or cooking spray.
02 - Spread English muffin pieces evenly in prepared dish. Top with diced Canadian bacon in a uniform layer.
03 - Whisk together 8 eggs, milk, 1/2 tsp salt, and black pepper in a large bowl until fully combined.
04 - Pour egg mixture evenly over muffin and bacon layers. Press down gently to ensure liquid absorbs.
05 - Cover dish with foil and refrigerate for at least 1 hour or overnight for optimal texture.
06 - Remove casserole from refrigerator while oven preheats. Sprinkle paprika evenly over surface.
07 - Bake covered with foil for 30 minutes at 375°F.
08 - Remove foil and continue baking 15-20 minutes until center is set and top is golden brown.
09 - Place egg yolks, lemon juice, 1/4 tsp salt, and cayenne in a heatproof bowl over simmering water.
10 - Whisk constantly for 2-3 minutes until thickened. Slowly drizzle in warm butter while whisking until sauce reaches glossy, thick consistency. Remove from heat.
11 - Let casserole rest 10 minutes before slicing. Serve warm topped with generous hollandaise sauce.