Start the oven at 175 degrees Celsius.
Butter a round baking form with removable edges.
Melt the butter in a casserole, add the chocolate and let it melt.
Add the saffron, salt and the sugar and mix well.
Add the eggs and the flour and mix the batter well.
Pour the batter in the baking form and place in the middle of the oven for 20 minutes.
Take out the mud cake and let it cool down.
Whip the whip cream and serve together with the cake.