Step 1

Spray a 9x13-inch baking dish with cooking spray.

Step 2

Arrange English muffin halves in a single layer in the bottom of the baking dish.

Step 3

Whisk together eggs, milk, salt, pepper, garlic powder, onion powder, and mustard in a bowl until well combined. Pour egg mixture over English muffins in the baking dish. Sprinkle chopped ham and 1 cup Cheddar cheese on top of the egg mixture.

Step 4

Cover with foil and refrigerate overnight.

Step 5

Preheat the oven to 400 degrees F (200 degrees C).

Step 6

Bake in the preheated oven until eggs are set, 30 to 35 minutes. Sprinkle with remaining 1/2 cup Cheddar cheese and chopped green onions. Slice and serve.