I am a bartender, i have served a version of this drink with great results. In order to get a real upside-down cake flavor, add amaretto. watch out for grenadine. Some complain of being too sweet. I serve it as a cocktail with a splash of cranberry. (offsetts the sweetness, adds the color that grenadine does.) I named it pineapple upside-down cake because it totally reminded me of one of my favorite desserts.  -  17 Feb 2008  (Review from Allrecipes USA and Canada)

A very, very good drink, but only if you make it right. First off, it MUST have Amaretto to make it taste like a real pineapple upside down cake. Usually a heavy splash or so. Second, use very good vanilla vodka. I've tried it with cheap vodka, and you can't taste the vanilla, which really makes or breaks this drink. You might be able to get away with regular vodka and a light splash of vanilla extract, but I really suggest the vanilla vodka.  -  03 Sep 2008  (Review from Allrecipes USA and Canada)

Very, very good. I added a touch of amaretto and it was just like a pineapple upside down cake. I'd make this again and again.  -  29 Oct 2008  (Review from Allrecipes USA and Canada)