Preheat the oven to 180 deg C (350 deg F) – spray a 20 x 30 cm ( 8 x 12 inch ) oven dish with cooking oil
Place 6 Slices of White Bread on the bottom of the oven dish – arrange half the Ham over the Bread – sprinkle over 1 cup Cheddar Cheese – repeat the layers
In a large bowl whisk together the Eggs, Milk, Mustard Powder, Onion Powder, Salt and Pepper – pour over the Bread/Ham/Cheese layers
Mix together the melted Butter and the Rice Krispies – sprinkle over the Egg mixture – bake 50 – 60 minutes until set (the Breakfast Bake will puff up, but settle again once it is removed from the oven)