Melt butter in a medium saucepan over medium heat.
Stir in peanut butter, vanilla, salt and white chocolate.
Bring to a boil and immediately turn down the heat, stirring frequently.
Cook on low heat until the mixture is smooth and all the chocolate is melted, about 3-4 minutes...
and remove from heat.
Mix in the confectionersâ€™ sugar with an electric mixer.
Beat until smooth.
Pour into a baking dish (approximately 8â€³ by 8â€³) and refrigerate for at least an hour, or until firm, and then cut into pieces.