I love a cake that has something hidden in it!  An ingredient that you might not have been expecting, or a layer of flavour hidden amongst sponge or icing.  Well, this is my version of a cake with a little surprise!

Bite through the soft sponge and creamy icing, and you’ll discover a tasty little puddle of custard!  Nobody was expecting this when my tasters ate the cakes, and there were a few chin dribbles, so a bit of forewarning or a piece of paper towel might not go amiss 😉
To a bowl, add 120g of butter, 120g of caster sugar, 120g of self-raising flour, 25g of cocoa powder, 1/2 a teaspoon of baking powder, 2 eggs, the finely grated peel of one orange and 1 teaspoon of orange extract.  Beat together until creamy and well combined.
I have used a special tin here, that leaves a hollow for the filling, but this really isn’t necessary, as I’ll explain later.  If you do have one of these tins, great, go ahead and grease the holes.  If not, just use a standard mini muffin tin.  Spoon the mixture into the holes equally, then bake in a preheated 180c oven for 15 to 20 minutes, depending on the tin size used.  Allow to cool in the tin for a few minutes after baking, then remove to a wire rack and allow to cool completely.
To make the custard, add 1 tablespoon of custard powder and 2 tablespoons of caster sugar to a pan.  Place over a high heat and gradually whisk in 125ml of milk.  Continue stirring until the custard thickens, then remove from the heat and allow to cool completely.  Placing a piece of cling film directly onto the surface of the custard will stop a skin forming.
When the custard is cool, use it to fill the hollow of the cakes, level with the surface.  If you used a mini muffin tin, your favourite friend here is an apple corer!  Just press it down gently into the top of the cake to remove a piece large enough to fill with the custard.  You get to eat the leftover piece too…bonus 😉  No apple corer, then just use a sharp knife to make a hole.
For the icing, beat together 100g of butter, 100g of melted, cooled plain chocolate, 125g of icing sugar and 1/2 a teaspoon of orange extract until creamy and smooth.  Pipe gently onto each cake to cover the custard, and top with some grated orange zest or decoration of your choice.  I had some jellied orange slices in the baking cupboard, so used those.