1Heat oven to 425°F. Line 17x12-inch half-sheet pan with foil; spray foil with cooking spray.
2Gently scrub potatoes, but do not peel. Using sharp knife, make 6 to 8 cuts from top of each potato to within 1/4 inch of bottom, being careful not to cut through bottom. Place potatoes, cut side up, on pan. Drizzle with oil; sprinkle with rosemary, salt and pepper.
3Bake uncovered 35 to 40 minutes or until potatoes are browned and tender. Sprinkle with cheese; bake 5 minutes longer.