Place half of the Canadian bacon in a greased 3-quart or 13x9 inch baking dish.
Top the bacon with English muffins and remaining bacon.
In a large bowl, whisk 8 eggs, milk, salt, garlic powder, and onion powder. Pour over top English muffins and bacon. Cover and refrigerate overnight.
When ready to bake, preheat oven to 375° F. Remove casserole from refrigerator while oven heats. Bake while covered for 35 minutes. Uncover and cook 10 more minutes.
After baking, make wells in 6 spots and cracks eggs over. Sprinkle with paprika.
Bake 10-12 minutes or until whites are mostly set, but yolks are still totally soft.
To make the hollandaise, cut the butter into four pieces, Place in a 1-quart glass measure or bowl. Cover with a paper towel and microwave on high until almost melted, about 45 seconds to 1 minute. Remove butter from the microwave and stir until completely melted.
Separate eggs, placing the yolks in a small bowl and setting the whites aside for another purpose. Beat the yolks well with a whisk or fork, then add to the butter and stir well. Add cream and 1 tablespoon lemon juice to egg mixture and stir well. Microwave mixture, uncovered, on high, until just slightly thick, about 1 to 2 minutes. Stop every 20 seconds to stir with a fork. Remove sauce from microwave and stir in extra lemon juice if desired
Drizzle hollandaise over casserole and serve.