Another option would be to use a double boiler, where the chips are melted but do not come in direct contact with the heat. To do this, use a small saucepan and place about a cup of water in the bottom. Place a slightly bigger heatproof bowl on top of the pan, and pour the chips in the bowl. The burner heats up the water in the saucepan and the steam from the water heats up the chips in the heatproof bowl. Butterscotch can take a while to melt, so be patient. Once there are only a few lumps left, take it off the heat and stir a few more times before pouring your chocolate over your chex mixture.