There are 2 items that sound very similar to this, one is the Glass Sipper (no L). That's an engraved glass you can purchase when you dine in Cinderella's castle. I think my kids ordered smoothies and for a few dollars more, you could purchase the special glass. That was over 2 years ago and the glass design is still in perfect condition after many washings.
The other item is the Cinderella's Chocolate Slipper, which is available throught the GF bakery. It's white chocolate in the shape of Cinderella's shoe and it comes filled with either white or dark chocolate mousse and some raspberries for the buttons on the shoe. All edible.
I'm guessing that the op is talking about the Chocolate Slipper.
Tammi