Whisk together the SunButter and sweetened condensed milk.
Beat the cream and vanilla together until stiff peaks form. Fold the cream into the SunButter mixture.
Layer the SunButter mixture into a 9- by 5-inch loaf pan with drizzles of the hot fudge sauce. Once everything is in the pan use a knife to gently swirl the fudge into the SunButter mixture. Cover with plastic wrap and freeze for at least 6 hours.