In a large bowl, combine the first seven ingredients; beat until light and fluffy. Transfer to a greased 11" x 7" baking dish.
For topping, combine the brown sugar and flour in a small bowl; cut in butter until crumbly. Fold in pecans. Sprinkle over sweet potato mixture.
Bake, uncovered at 350 degrees for 30-35 minutes or until a thermometer reads 160 degrees.