Put unwrapped caramels and the water in a medium saucepan. Cook until caramels are melted and smooth, stirring constantly. Remove from heat.
Arrange apple slices on a pizza plate or pan. Use a spoon to drizzle caramel mixture over apples.
Put chocolate pieces and shortening in small saucepan. Cook over medium-low heat until mixture is melted and smooth, stirring constantly. Use another spoon to drizzle the chocolate mixture over the caramel-covered apples. Sprinkle with nut topping. Let stand at room temperature for up to 10 minutes. Makes 6 to 8 servings.