Line two large baking sheets with parchment paper. Set aside.
To a large bowl, add peanuts, chow mein noodles, and potato chips.
In a separate, microwave-safe bowl, melt the butterscotch chips. Then, stir in peanut butter.
Pour the melted butterscotch and peanut butter into the bowl with the peanuts, chow mein noodles, and chips. Stir together. (The chips should crush naturally.) Mix until all ingredients are fully coated.
Using a spoon or cookie scoop, drop dollops of the mixture onto the parchment-lined baking sheets. (If the mixture has hardened before you can spoon it all onto the baking sheets, simply microwave the mixture for 15-20 seconds, or until the butterscotch has melted again.) This recipe made 24 haystacks. Depending on the size of the clusters, the number of haystacks may vary.
Let cool until firm (10-15 minutes).