HEAT oven to 375°F. Place 1/4 cup butter in each of 2 (9-inch) round baking pans. Bake 5 minutes or until melted. Tilt pans to coat bottoms of pans with butter. Add 1/3 cup brown sugar to each pan, sprinkling evenly. Arrange apple slices in prepared pans, beginning in center of pans and working out, slightly overlapping slices to create a spiral pattern. Set aside.
BEAT applesauce, milk, oil and eggs in large bowl with electric mixer on medium speed until blended. Add cake mix and cinnamon. Beat on medium speed 2 minutes.
SPOON batter evenly into prepared pans. Spread evenly. Bake 25 to 30 minutes or until toothpick inserted into cake comes out clean. Cool 5 minutes. Invert cakes onto serving platters. Cool completely. Serve with whipped topping, if desired.
Serving Size (1 slice of 16), Calories 280 (Calories from Fat 120), Total Fat 13g (Saturated Fat 4.5g, Trans Fat 0g), Cholesterol 50mg, Sodium 290mg, Total Carbohydrate 39g (Dietary Fiber 1g, Sugars 25g), Protein 3g; Percent Daily Value*: Vitamin A 4%, Vitamin C 0%, Calcium 15%, Iron 2%.
*Percent Daily Values are based on a 2,000 calorie diet.