In a medium pan, saute mushrooms and onion in 3 1/2 tablespoons of the butter until just tender, about 5 minutes. Stir in the bread crumbs, Parmesan, salt and pepper.
Butter the bottom and sides of a 10 inch deep dish pie pan with remaining butter. Press mushroom mixture into pan evenly on bottom and sides.
Sprinkle shredded cheese over the mushrooms.
In a blender, beat together cream cheese, eggs and hot pepper sauce until well incorporated. Stir in diced ham.
Pour over the shredded cheese and bake 30 minutes or until set in center.