Grease your slow cooker with a pat of butter and pour in about half of the cooked noodles.
Layer on six slices of cheese, two cups of the Monterrey jack cheese and one cup of the shredded cheddar cheese. Repeat this layer again. Generously sprinkle the Parmesean cheese and breadcrumbs on top. Pour milk down the sides of the of the mixture, taking care not to pour it ontop of the layers.
Cover and slow cook on high for 3 hours or until the breadcrumbs crisp up and the milk has evaporated.