How to make
Heat the oven to 350°F (175 °C) with the fan on. Prepare a square cake form, 9″ (23 cm) per side. Cover it with aluminum foil completely and butter it.
Beat the butter with the sugar in a bowl with a mixer until whitened. Add the vanilla, flour and salt. You're going to get a crumbly dough, remove the mixer, put it in the cake form and form a nice layer with your hands. Poke holes in it all over, so it doesn't rise during baking.
Bake at 360°F (180 °C) for 20 min. or until the sides separate from the cake form and the dough gains a nice golden color. Let it cool in the form and pour the Dulce De Leche over it, smooth it out with a spatula. Keep it in the fridge for about 1 hour until it sets.
Melt the chocolate in a water bath and cool it to a state where you can pour it, i.e. it needs to be well tempered. Pour it over the caramel, smooth it out with a spatula and put it in the fridge again to harden for the final time.
Cut it into small, square pieces with a very sharp knife. You can store the cake in the fridge for about 1 week.
Notes:
1. Once the chocolate cools, but before it hardens completely, pour it over the caramel, so you can spread it out well with the spatula.
2. I used ready-made Dulce De Leche caramel but you can make your own from a can of sweet condensed milk - put it in a water bath, cover with aluminum foil and boil on moderate heat for about 1 1/2 hours to obtain a nice, full, golden caramel, while stirring several times. It needs to have a thick consistency as well.
I can't tell you exactly why this cake has such a funny name but it's probably due to the rich taste of the caramel and chocolate on top of the beautiful butter dough.
