How to make
Boil the condensed milk in a pot with at least 1 1/4 inches of water added to it. Boil 3 hours on low heat, adding more water, then leave it to cool for 2 hours before opening the lid.
Beat the cream with the softened butter. Add 2 cups of flour that you've sifted with the baking powder. Stir and add the remaining flour. Knead a soft dough and divide it into 7 parts. Form each one into a ball and leave it in the fridge for 1 hour.
Roll out each ball into a layer, for a total of 7, each one 1/16 thick. Bake 10 min. at 390°F (200 °C). Let them cool.
Prepare the cream by mixing the powdered sugar with the cocoa and vanilla. Add the yolks and beat everything to a cream. Add the softened butter and stir. Pour the condensed milk in lots and beat to a smooth cream.
Grate the chocolate. Smear each cake layer with cream and arrange them one atop the other. Smear the cake with cream and sprinkle the sides and top with chocolate. Leave in the fridge for 8 hour before serving.