Preheat oven to 400degrees. Scrub sweet potatoes; pierce several times with a fork. Place on a foil-lined 15x10x1-in. baking pan; bake 1 hour or until tender. Remove from oven. Reduce oven setting to 350degrees., When potatoes are cool enough to handle, remove and discard peel. Mash potatoes in a large bowl (you should have about 6 cups mashed). Stir in eggnog, raisins, sugar and salt. Transfer to a greased 11x7-in. baking dish., For topping, in a small bowl, mix flour, oats, brown sugar, pecans and spices; stir in butter. Sprinkle over sweet potatoes. Bake, uncovered, 30-35 minutes or until heated through and topping is lightly browned.