I've been wanting heart-shaped truffles to be a family tradition and I tried doing it last year and couldn't make it work. This year - we did it and here's how:
Take 1 package of Oreos (we used the off brand "Duos") and one package of cream cheese. Mash or blend the oreos up into powder then mix well with the cream cheese until the texture is uniform. Then, roll it out and put it in the freezer until it sets up...a couple hours is probably enough but it worked best if I did it overnight. Use a cookie cutter to punch our your hearts.
Dip in chocolate with a skewer - the melted chocolate is warm and can make the truffles mushy and loose their shape if you're not careful. So, take them right out of the freezer and dip them as fast as you can so they don't warm up too much.
After the excess chocolate drips off, slide a fork between the skewer so you can get the heart off without ruining its shape and place it on a pan to freeze.
We like our truffles best frozen but you can keep them in the fridge too.