Lightly spray a 9x13" pan with cooking spray. Set aside.
In a large microwave-safe bowl, microwave butterscotch chips, light corn syrup, butter, and mini marshmallows on high for 2-3 minutes or until smooth. Stir after each minute.
Add the pumpkin pie spice and the Cheerios and quickly mix them in until they are evenly coated.
Press the Cheerio mixture into your prepared pan. Press with a spoon (or your hands) that has been lightly sprayed with cooking spray.
In a small bowl, melt the white chocolate chips in the microwave. Heat at 30-second intervals, stirring in between. Heat until smooth; then stir in the cinnamon.
Drizzle the chocolate evenly over the bars and sprinkle with toasted pecans and candied ginger.
Refrigerate for about one hour or until firm. Slice and serve. Store in an airtight container.