Preheat oven to 375°F. Toss potatoes with melted butter, thyme, garlic salt and white pepper in medium bowl.
Mix cream cheese and cream until well blended. Layer 1/3 of potato mixture in 1 1/2-quart baking dish. Spread 1/2 of the cream cheese mixture evenly over potatoes. Repeat layers, ending with potatoes. Mix Parmesan cheese and bread crumbs in small bowl. Sprinkle over potatoes. Cover with foil.
Bake 40 minutes. Remove foil. Bake 15 minutes longer or until potatoes are tender and top is golden brown.