Place potatoes in a pot, cover with water and boil until fork tender, about 20 minutes; cool, then cut into fourths.
Heat oven to 400°.
Combine ranch dressing and melted butter in a bowl.
Combine the paprika, white pepper and salt; mix half of the spice mixture into the dressing mixture and then combine that mix with the potatoes.
Pour potato mixture into a greased, 9x13-inch casserole dish, or a pan large enough so that potatoes form a single layer; sprinkle the parmesan cheese evenly over the top and sprinkle the remaining spice mixture over that.
Bake on middle rach of oven for 20 minutes, or until golden brown.