Place chocolate and butterscotch chips, butter and cream in a saucepan and melt over low heat stirring constantly. Make sure to scrape the bottom of the pan so the chocolate doesn’t burn. Set aside to cool.
Place powdered sugar and peanut butter in a mixer fitted with the whisk attachment and beat until combined on medium speed. Add the cooled chocolate mixture and vanilla and mix on medium speed until combined. Add the yogurt and mix until smooth. Scrape the sides of the bowl throughout mixing for an even consistency.