In a small bowl, stir together paprika, brown sugar, black pepper, onion powder, thyme, rosemary, garlic powder, and cayenne pepper.
Slice the sweet potatoes in half lengthwise. Brush each half with olive oil. Rub the seasoning mix over the cut surface of each half. Place sweet potatoes on a baking sheet, or in a shallow pan.
Bake in preheated oven until tender, or about 1 hour.
