Baked Potato Skins

I think I finally found the recipe I've always used for potato skins on Food.com.  I'm glad I did too because I think the amounts of spices I originally guessed at were way off.  I made some adjustments though since I always inevitably ran out of olive oil mixture when I followed the recipe.

Ingredients
4 large russet potatoes
1/4 cup olive oil
1/2 tsp Kosher salt
1/8 tsp fresh ground black pepper
1/2 tsp paprika
1/2 tsp garlic powder
2 tbs Parmesan cheese, finely grated
2 cups Cheddar cheese, grated
1 cup sour cream (optional)
2 tbs green onions or chives (optional)

Directions

1. Preheat the oven to 400 degrees F (200 degrees C).
2. Pierce potatoes with a fork to allow steam to escape, and wrap each in aluminum foil.  Bake the potatoes for 1 hour. Remove the potatoes from the oven, but keep the oven on. Slice the potatoes in half lengthwise, and let them cool for 10 mins. Scoop out most of the potato flesh, leaving about 1/4 inch of flesh against the potato skin (you can save the potato flesh for another use, like mashed potatoes).
3. Combine olive oil, salt, pepper, chili powder, paprika, garlic powder, and Parmesan cheese in a small bowl.  Brush oil mixture evenly onto each of the potato skins (I highly recommend getting a silicone pastry brush for this -- OXO makes a good dishwasher-safe one).  Place on a baking sheet and cook in the preheated oven for 7 minutes. 
4. Remove baking sheet from the oven, flip the potato skins, and brush another layer of oil mixture onto each of them.  Place back in the oven to cook for another 7 minutes.  The skins should be crispy by the time this is done.
5. Remove baking sheet from oven, fill potato skins with cheddar cheese, and put the baking sheet back in the oven for a final 1-3 minutes -- just long enough to melt the cheese.
6. Sprinkle green onions or chives onto potato skins and serve alongside sour cream.  They're also good with ranch dressing.