Heat oven to 400°F. Pierce sweet potatoes with fork. Cut top off bulb of garlic. Place garlic on small piece of foil; drizzle with oil. Wrap garlic in foil. Bake potatoes and garlic 1 hour to 1 hour 15 minutes or until potatoes are tender. Cool.
Reduce oven temperature to 350°F. Spray 13x9-inch (3-quart) glass baking dish with cooking spray. Peel sweet potatoes. In large bowl, mash potatoes. Squeeze garlic pulp into potatoes. Add milk, 1/2 teaspoon of the salt and 1/2 cup of the melted butter; mash until blended. Spread mixture in baking dish.
In medium bowl, mix bread crumbs, cheese, nuts, rosemary, paprika, pepper, remaining 1 teaspoon salt and remaining 1/2 cup melted butter. Sprinkle over potato mixture.
Bake uncovered 20 to 25 minutes or until topping is golden brown.