Whip the yogurt, peanut butter, and optional sweetener until smooth. Add a handful of mini chocolate chips if desired. Drop blobs of the mixture onto a parchment lined tray. Press a popsicle stick or small spoon into each, then smooth down. If using, sprinkle a few chopped peanuts onto each pop. Freeze until firm.
Carefully melt the chocolate chips, then stir in the optional oil for a smoother sauce. Dip the peanut butter Buster Bars into the melted chocolate. Freeze to set the chocolate shell.
