Multiple ideas cake

 This cake is the result of a rainy Saturday morning with too much time on my hands and too many rain showers outside.
I was at home, quite bored and disappointed as normally I would have gone to Dappelmarkt to find a nice cut of fabric I have been looking for (projects projects projects!) but the weather was too unstable and, in the very end, me too tired after a rather stressful week at work.
The same morning I had been reading my feedly where I keep the best list in terms of inspiration: BLOGS. Many. Blogs. They are mostly food blogs, but I also have a couple of lifestyle ones in my top 10. Also, I have my bunch of favourites that I haven't changed since years. Sadly some of the girls behind them are currently taking a break from their respective blogs and they don't post stuff that often anymore, but their legacy is on the web for us to enjoy. I am sure that there will be occasions to mention my sources again in the future and, since many of them are Italian, I will happily sacrifice myself to translate their recipes whenever I feel that they are particularly interesting.

So I was needing something to fill up my day and I decided to try the trick I read about the same morning. It was about a certain crumble Nutella cake, and the trick itself is simple yet quite ingenious: freezing the Nutella in the same tin we will use to bake the cake, in the shape of a flat disc, and later use it frozen to create the filling between two layers of crumble cake. What for? The frozen Nutella would melt in the oven, but keeping the creamy texture it would normally lose after being baked. Not bad, right?

Too bad I had not a single drop of Nutella at home. We are no big Nutella-eaters, and I usually fall more easily for real chocolate. For a moment I considered the idea of going to the closest supermarket and quickly get a jar of the magic cream, but again rain showers put me down and I gave up.

Instead, I thought of that excellent organic chocolate bar we had purchased a few weeks back: is there maybe a leftover bit I can use for my cake? Well. Was I really serious when I believed that a chocolate bar could last so long in our house? Or, rather, in EVERY house? Ahem.

It ended up with the easiest solution but all in all it was a win-win.
I simply made a dense custard cream using 500 ml of milk, a couple of spoonfuls of granulated sugar, grated lemon zest, a spoonful of flour, mixing it well with a whisk on medium heat until it became thick enough (from the moment it started to thicken up I boiled it only a minute more).
While the custard was cooling down, I made my crumble dough, just use your favourite one.
Compose the cake over a parchment-lined tin (mine is 22 cm) by layering the dough with the custard: reserve a handful of crumble for the top. Bake until golden, let it cool down, and enjoy a well-deserved slice with a cup of tea.