1. Cut apples into quarters. Core each quarter and cut into 1/2-inch-thick slices.
2. Melt butter in large nonstick skillet over medium heat. Add apples; cook 4 minutes, stirring occasionally.
3. Combine apple juice, brown sugar substitute and cinnamon; pour over apples. Simmer 5 minutes or until apples are tender and sauce thickens. Transfer to serving plates; top with walnuts.