Lightly spray a 9x13" casserole dish with non stick cooking spray. Set aside.
Roughly chop the muffins slices. Then do the same with the Canadian bacon. Set aside.
Add half of the chopped muffins to the bottom of the dish, in a single layer. Spread half the chopped bacon over top, followed by one cup of the cheese.
Repeat the layers adding the remaining chopped English muffins over top, followed by the rest of the meat. Sprinkle another cup of shredded cheddar evenly out over top.
In a large mixing bowl, crack the eggs. Add in the milk, salt, & pepper and whisk together until the mixture's smooth.
Pour the egg mixture evenly out over the casserole.
Using cling wrap, tightly seal the dish and refrigerate for two hours or up to overnight.
Remove the plastic wrap, sprinkle the remaining cheese evenly out over top of the casserole and bake at 325 degrees for 45-50 minutes.
Let the casserole rest for 5 full minutes before slicing & serving.