Melt 4 tablespoons butter in large saucepan. Stir in flour until smooth. Add milk, stir constantly until bubbly. Add cream cheese. After melted stir in salt, pepper, and mustard. Add cheddar, stir, remove from heat.
Combine pasta, ham, and sauce in baking dish.
In a separate small pan melt 2 tablespoons butter and toss breadcrumbs and parsley; sprinkle over mac.