Wash sweet potatoes, and place on a baking sheet; prick with a fork. Bake at 400° for 1 hour or until almost tender. Remove from oven. Let stand 45 minutes or until cooled.
Meanwhile, peel and core apples. Slice apples into 1/3" thick wedges; toss with lemon juice in a bowl.
Peel cooled potatoes, and slice 1/3" thick. Arrange potatoes and apples alternately in a greased 13" x 9" baking dish. Pour remaining lemon juice over potatoes and apples.
Combine brown sugar and next 6 ingredients in a saucepan, stirring well. Bring to a boil over medium heat, stirring occasionally; boil 2 minutes or until slightly thickened. Pour glaze over potatoes and apples. Bake, uncovered, at 400° for 30 minutes.
Remove from oven; baste with glaze in bottom of dish, and sprinkle nuts across top. Bake 14 to 15 more minutes or until apples look roasted. Baste with glaze just before serving.