Put the butterscotch, chocolate chips, and peanut butter in a pot over another pot of water. Bring the water to a boil, then lower the heat to low, and stir the mixture, until melted.
Transfer the mixture to a large bowl, and add the chow mein noodles and peanuts. Stir to combine.
Prepare a large baking tray with parchment paper. Drop about 2 tablespoons of the mixture onto the tray to form the haystacks. Put the tray into the fridge for about 40 minutes, until the chocolate hardens.