For the Granita: In a shallow 8-inch square pan, stir the applesauce and lemon juice together and spread the mixture evenly in the pan. Place the pan in the freezer for at least 1 hour.
For the Sauce: In a bowl, combine the yogurt, maple syrup, and cinnamon. Chill the sauce until ready to serve.
Remove the granita from the freezer. With a fork, scrape the surface of the granita to gently fluff it up. Serve immediately, in dessert glasses or dishes, drizzled with yogurt sauce.