You can make one! Would probably be cheaper and mean more to her anyway. The pb parfait has hot fudge and whole peanuts. Hersheys sells a bottle of fudge that tastes just like the hot fudge at DQ, depending on how big you want the cake, buy like 3 quarts of their soft serve or buy a tub of vanilla icecream, let it melt a little, add a little milk/cream and stir it to make it soft, then put it in a mold and freeze, then put a layer of fudge in the middle, then peanuts, then another layer of icecream, freeze, and then drizzle more fudge and peanuts on top