These candy-like bars store best in the fridge (our tests showed they became stale at room temperature after one day). After chilling, let the bars stand at room temperature for 15 to 20 minutes before serving.
Grease a 8x8x2-inch baking pan. In a 3-qt saucepan combine sugar and corn syrup. Cook over medium heat, stirring constantly, until sugar dissolves and mixture comes to a boil. Remove from heat. Stir in peanut butter until mixture is smooth and thoroughly combined.
Before opening bag of corn chips, lightly crush chips in the bag with your hands. Add corn chips to peanut butter mixture and stir until well-coated, continuing to break up the chips as you stir. Transfer mixture to prepared baking pan, spreading evenly. Place a piece of wax paper over the mixture and press to make a firm, even layer.
Combine chocolate and butterscotch chips in a small microwave-safe bowl. Microwave on high 30 seconds; stir. Microwave 30 seconds more; stir again. Continue cooking in 10-second intervals until mixture is melted and smooth. Pour over corn chip mixture in pan, spreading evenly. Let stand 2 hours or until firm. Cut into 4x1-inch bars. Store in an airtight container in the refrigerator up to 1 week or freeze up to 3 months.