Add the vanilla, butterscotch chips, white chocolate chips (you may wish to start with 1 cup each of the butterscotch chips and white chocolate chips and increase to taste. I use 1 1/2 cups of each and the peanut butter is very sweet), the optional salt (I do not add salt; the salt from the honey roasted peanuts is enough for me) and process for 2 to 3 minutes, or until smooth and incorporated. I add the vanilla and baking chips all at once through the feed tube with the machine running, but if using a weaker or older food processor, sprinkling them in more slowly may prevent your machine from struggling. I do not melt them first or do anything other than simply adding them in whole. The power of the machine, coupled with the heat the peanut butter has taken on after 5 minutes of blending, is enough to incorporate them perfectly smoothly.