Preheat oven to 375°.
Combine apple, apple juice, 1 tablespoon sweetener, lemon juice, cinnamon, and nutmeg; toss lightly to coat apple. Place in an 8-inch square baking dish.
Combine oats, nuts, remaining 1 tablespoon sweetener, and margarine; sprinkle over apple mixture. Bake at 375° for 30 minutes or until apple is tender and topping is lightly browned. Serve warm. Top with ice cream, if desired (ice cream not included in analysis).