1) Melt the chocolate with the butter in a double boiler (take care that the water does not touch the container so that the chocolate does not spoil),
2) Place in a bowl, add the sugar, the eggs one by one, the flour and the cocoa, add, little by little, always mixing and add the hot water.
3) Pour into a buttered pan and take to an oven with medium-low flame, the test to see if it is is to move it and keep it still.
Or stick a toothpick and see that it comes out clean. Let cool and unmold.
For the filling:
1) In a bowl mix all the ingredients, always gently until the cream is formed.
2) You can cut the cake in half or in three layers as you prefer, and fill with the ready mix, arrange on a tray.
On the surface of the cake, cover with the same cream as the filling.