Interesting cake. I found it very dense and would add Baking Powder next time. The lemon flavour needed a bit more zip so I would add some lemon juice and more zest / rind.
I left the sugar out of the topping so it was just a chocolate ganache.
Was well received but a bit messy to cut!
I think the lemon curd gives the cake that dense and almost sticky texture. I like it though.
you could always do lemon zest in the cake and do lemon curd between the layers!