Preheat oven to 425 degrees. Wash and pat dry potatoes, removing any blemishes. Prepare a large baking sheet with an elevated rack (I used my cooling rack, but be careful to make sure it is oven safe and not covered in plastic; broiler pans work well too). Coat lightly with cooking spray.
Mix powdered buttermilk through Parmesan cheese in a small bowl. In a large bowl coat potatoes with 2 tablespoons extra virgin olive oil. Toss buttermilk mixture with potatoes covering as much surface area as possible. Set aside large mixing bowl and remaining buttermilk mixture.
Arrange in a single layer on elevated rack. Bake for 15 minutes in the center of the oven. Check to make sure the tops are not burning. If they are lower oven rack and temperature to 400 degrees or cover with a sheet of aluminum foil.
Remove after 15 minutes and return potatoes to large mixing bowl with leftover buttermilk mixture, add 2 tablespoons extra virgin olive oil and toss again.
Return to elevated cooking rack and oven for 5-10 minutes or until you can easily insert a fork or knife into a potato.
Remove and allow to cool for several minutes before serving.
If you've tried this recipe, come back and let us know how it was!