Preheat oven to 375. Use a 3½ round cutter to cut rounds from tortillas. You should be able to get 4 rounds per tortilla. Brush 1 side of each tortilla with butter. On a plate mix together cinnamon, SweetN Low, and salt, and sprinkle buttered side of tortillas with mixture. Turn a muffin tin upside down. Fold tortillas into taco shapes with cinnamon on outside, and place between muffin cups so they stand upright. Bake until crisp, 10-15 minutes. While taco shells bake, in a medium saucepan over medium heat combine apples, lemon juice, SweetN Low, cinnamon, and ¼ cup water. Cook, stirring, until apples are just tender, about 5 minutes. Stir in cornstarch mixture and boil 1 minute, until thickened. To serve, fill taco shells with apple pie mixture and top with whipped topping.
