Using a sharp 8- to 10-inch skewer, pierce a potato lengthwise all the way through the center. Repeat with another potato on the same skewer. Repeat with remaining potatoes.
On a cutting board, slice an angled slit at the very top of one potato. Keeping the knife in place, slowly rotate the potato. The spirals will start to form. Try to keep the spirals as thin as possible. Once the spiral is complete, carefully pull the layers apart on the skewer. Repeat with other potato on skewer, and then remaining potatoes on skewers.
In a small bowl, combine chili powder, sugar, cumin, garlic powder, salt, pepper, oregano, and crushed red pepper.
Set the skewers on the edges of a baking dish so that the potatoes don't touch the bottom of the dish. Drizzle with oil and sprinkle with desired amount of seasoning blend, rotating to cover as much potato as possible. Bake for 25 to 30 minutes or until lightly browned and crispy, turning occasionally.