Peel, dice, and wash the potatoes. Cook the potato cubes in boiling water until tender; drain.
In a large bowl mash the potatoes. Add the remaining ingredients and blend well.
Spray a 3-quart casserole or 9x13 inch baking dish with nonstick spray. Pour the potatoes into the casserole dish and bake at 350 degrees for 20 to 25 minutes or until top starts to brown slightly.