What is on top of this and how do you make it?
Most often they are called tuiles and they can be made in a number of ways, in some cases they are biscuit based or they can be made by melting sugar on a non-stick surface. and then cutting while the sugar is still warm and pliable. 

If you wanted to make a classic biscuity tuile there is a recipe here:

http://www.finecooking.com/recipes/classic-tuile-cookies.aspx

For a sugar only variety you could consider using some fine sugar and a blow torch, in a similar way to a creme brûlée topping and using a metal cookie cutter to get the desired shape. 

The benefit of the classic tuile recipe is that it can be adjusted in order to add flavourings e.g. vanilla or even spices.

Parmesan under a grill can also form a tuile as long as the grill isn't set to too high a temperature (chocolate and cheese go pretty nicely together...)