Wash yams; drain but do not dry. Set in slow-cooking pot. Cover and cook on low for 4 to 6 hours (depending on size and shape). Cool, peel and place in large bowl. Mash until smooth. Add butter, 1/4 cup brown sugar, lemon peel, juice and salt; mix well. Spoon into greased 1 1/2-qt. Baking dish. Sprinkle remaining 1/8 cup brown sugar and almonds on top. Bake in 350 F oven for 40 to 50 minutes.