Preheat the oven to 350 degrees F. Lightly grease 9 by 13 by 2-inch pan.
Make the crust by combining flour, confectioners' sugar, and salt in a large bowl.
Cut in 2 sticks of butter to make a crumbly mixture. (See Cook's Note)
Press the mixture into the prepared pan. You may need to dip your fingers into a little flour or confectioners' sugar to keep the dough from sticking to your fingers. Bake for 15 to 20 minutes.
In a large skillet, melt the remaining stick of butter over medium heat. Add the apples, and cook for 3 minutes. Stir in 1 cup sugar, 1/2 teaspoon cinnamon, and lemon juice; cook for 3 minutes. In a small bowl, soften the gelatin in cold apple juice, then add it to apples, and cook for 15 minutes. Spoon the mixture evenly over the prepared crust and bake for 10 to 15 minutes. Let cool, then cut into squares. Serve with vanilla ice cream and Cinnamon Whipped Cream.
In a medium bowl, beat the heavy cream at medium-high speed with an electric mixer until thickened. Gradually beat in the confectioners' sugar and cinnamon, beating until stiff peaks form. Cover, and chill until ready to use.
Add water 1 tablespoon at a time if the dough is too dry.