Preheat oven to 400°F.
Butter 13x9x2-inch baking dish.
Bring large pot of water to boil; add yams. Cook about 4 minutes or until water returns to simmer; drain. Rinse under cold water.
Arrange yams in prepared dish. Season with salt. Pour syrup over yams. Dot with 3 Tbsp. butter. Cover and bake about 25 minutes or until yams are almost tender.
Mix flour and brown sugar in medium bowl. Add remaining ½ cup butter. Cut in until mixture resembles coarse meal. Add pecans; mix.
Sprinkle pecan mixture over yams; bake 20 minutes or until tender.
Note: Sweet potatoes may be substituted.