Step 1

Place half of the Canadian bacon in a lightly greased (with cooking spray) 13-x 9-inch baking dish. Top with English muffin pieces; top with remaining Canadian bacon. Whisk together 8 eggs, garlic powder, salt and 2 cups of the milk in a large bowl. Pour over Canadian bacon mixture in baking dish; cover with plastic wrap and refrigerate at least 4 hours or up to 24 hours.

Step 2

Preheat oven to 375 degrees F. Remove casserole and let stand at room temperature while oven preheats. Remove plastic wrap and sprinkle casserole with paprika; bake in preheated oven until set, about 35 minutes. Sprinkle with parsley.

Step 3

While casserole bakes, melt butter in a small saucepan over low. Cook, swirling pan until butter turns light golden, 1 to 2 minutes; pour into a small bowl and set aside.

Step 4

Whisk together buttermilk, cornstarch and cayenne pepper in a heavy-bottomed, medium saucepan until smooth. Whisk in remaining 2 eggs and 1 cup milk. Cook over medium-low, whisking constantly, until mixture comes to a simmer; cook, whisking constantly, 15 seconds. Remove from heat, and whisk in lemon juice and reserved butter. Serve warm lemon-butter sauce with casserole.