In a small bowl, mix Parmesan cheese and bread crumbs; set aside.
In a medium-sized bowl, combine mashed potatoes, cream cheese, eggs, onion, and flour. Beat with a mixer on low speed until blended. Beat at high speed until mixture is light and fluffy. Add salt and pepper.
Pour potato mixture into a greased casserole dish. Sprinkle with bread crumb/Parmesan cheese mixture.