Eggs Benedict Casserole

Name: Eggs Benedict Casserole
Ingredients: 2 (6 ounce) packages uncured Canadian bacon, chopped; 1 (12 ounce) package whole-wheat English muffins, split and cut into 1-inch pieces; 10 large eggs; ½ teaspoon garlic powder; ¼ teaspoon kosher salt; 3 cups 2% reduced-fat milk, divided; ¼ teaspoon paprika; 3 tablespoons torn fresh flat-leaf parsley leaves; 2 tablespoons unsalted butter; ½ cup low-fat buttermilk; 2 tablespoons cornstarch; Pinch of cayenne pepper; 2 tablespoons fresh lemon juice (from 1 large lemon)