Preheat oven to 400 F. Slice potatoes into 1/4" rounds, pat dry with paper towels and place into a large resealable plastic bag. Set aside.
Combine garlic powder, celery seed, paprika, salt, pepper and cayenne and mix well. Sprinkle on top of potatoes in the bag and shake the bag well to coat the outsides.
Lay the potatoes in a single layer on a baking sheet lined with non stick aluminum foil or sprayed with non stick spray so they don't stick. Drizzle tops with olive oil.
Flip over each potato slice. Bake for 35-45 minutes or until the outside is crispy and the inside is soft. If you want to melt cheese on top, flip over after 35 minutes, sprinkle shredded cheese on top and bake remaining 5-10 minutes until melted and crispy. Immediately loosen from baking sheet with a spatula.