I used a mini-muffin pan and this recipe, but I also added extra vanilla, the grated rind of two thin-skinned oranges and some orange blossom water. Then I made two different toppings.
The first one was some plain 70% cocoa dark chocolate, melted, with a Jaffa on top.
The second was the best, definitely. The icing was plain icing sugar, mixed with enough vanilla essence, orange juice and orange blossom water to a thick dollopy consistency. Then on top I made some caramelised orange rind: thinly sliced rind in a saucepan with about half a cup of sugar and the same of water, and some vanilla extract, or a split pod. Boil, then reduce till sticky.