In a large mixing bowl, combine the Rice Chex cereal and chopped dried apple slices. Set aside.
In a small saucepan over low heat, melt the caramel sauce until it becomes smooth. Stir in the vanilla extract and ground cinnamon.
Pour the melted caramel mixture over the cereal and apple slices. Gently stir until all the cereal is evenly coated.
Transfer the mixture to a large zip-top bag or a bowl. Add the powdered sugar and shake or stir until the cereal is well coated.
Fold in the mini chocolate chips and chopped pecans, if using.
Spread the puppy chow mixture onto a baking sheet lined with parchment paper to cool for about 30 minutes.
Once cooled, break into pieces and serve.