Line a 9 x 13-inch pan with parchment paper or lightly grease it. Place the crispy rice cereal and lightly crushed dried apple pieces in a large mixing bowl.

Melt the butter in a large saucepan over low heat. Add the mini marshmallows and stir constantly until nearly smooth, then remove the pan from the heat immediately.

Stir the vanilla extract, apple-pie spice, and optional salt into the warm marshmallow mixture. Pour it over the cereal and dried apples, then fold gently until everything is evenly coated.

Transfer the mixture to the prepared pan. Press it into an even layer with lightly buttered hands or a piece of parchment paper, taking care not to pack it too firmly.

Warm the caramel sauce briefly if it is too thick to pour. Drizzle the caramel over the treats, or fold about 1/4 cup into the cereal mixture and reserve the remaining caramel for the top.

Let the treats cool and set at room temperature for at least 30 minutes before cutting into squares. For the neatest portions, use a lightly greased sharp knife and wipe it clean between cuts.