Sarah James at Instructables writes:

Try this homemade magic shell ice cream topping recipe, and be amazed at how simple and delicious (and customizable!) it is.

Using only two ingredients, you can make a marvelous crispy chocolate coating for your ice cream.   Stick with basic chocolate, or spice it up with any flavor combinations you can dream of. It’s so easy and addictive, you won’t be able to resist making up several batches and sharing them with your friends. In fact, the basic recipe I used is vegan! (for all of your non-dairy frozen treats)