Pre-heat the oven to 425˚F.
Using a small sharp knife, score the potatoes.
Place the butter in an 9-inch x 13-inch baking dish and set in the oven for 5 minutes, until the butter is melted.
Remove the dish from the oven; add parmesan cheese and spices; combine until they form a paste.
Spread with a spatula to coat the bottom of the pan with the paste.
Place the halved potatoes cut side down in the baking dish.
Brush with the reserved melted butter on top.
Bake until golden brown and crispy; about 35 minutes.
Remove from the oven; separate the potatoes and serve with a ranch dip, if desired.
