Heat oven to 350°F; spray a 9x13-inch dish.
Whisk eggs, milk, garlic powder, paprika, salt, and pepper in a large bowl.
Layer bread, pork, peppers, onion, and 1½ cups cheese evenly in dish.
Pour eggs evenly over filling; press gently to soak bread.
Cover with foil; refrigerate at least 2 hours or overnight, or freeze for later.
Bake covered 30 minutes; uncover, top with ½ cup cheese, and bake 15 minutes until golden and set.
Rest 10 minutes. If frozen, thaw refrigerated overnight before baking and add 10-15 minutes cooking time.