Bottom Layer – Combine the butter, sugar, cocoa, egg and vanilla in a large heavy saucepan and stir over LOW heat until the mixture becomes custard-like (it will! after a couple of minutes).  Remove the pot from the heat and add in the graham crumbs, coconut and pecans.  Mix well then press it all into a lightly sprayed 8 x 8 cake pan.  Cover and chill until you’re ready with the middle layer – you can do the layers days apart if that’s easiest.

Middle Layer – In a small bowl, stir the custard powder into the milk until it’s dissolved and set it aside.  In a medium bowl cream together the butter and icing sugar (I used my hand beaters), then add in the custard mixture and beat it all together.  Spread this evenly on top of the bottom layer then cover it and chill it until it’s firm.

Topping – Carefully melt the chocolate and butter in the microwave, in 30-second increments, stirring in between – giving it a good stir should bring it all together and keep the mixture smooth.  Pour this over the cooled cake and use the back of a spoon to quickly smooth it out and make an even layer.  I then allowed this to chill for about an hour, so that it had hardened, but wasn’t rock-solid, then I sacrificed one beautiful edge in order to pry the whole pan of squares out – intact – onto a cutting board.  You can wait and do this anytime but then you risk cracking the chocolate when you cut them up.  Either way cut the pan into squares and serve – or eat – as desired.