Drain the cherries and raspberries and mix them together in a large bowl (collect the juice). Heat about half to three quarters of the juice and thicken with the cake icing. Then mix carefully with the fruits in the bowl.
Whip the cream until stiff and mix with the yoghurt. Pour half of the mixture over the slightly cooled fruit, smooth out and sprinkle with cane sugar (a little more generously). Then add the rest of the mixture and sprinkle with cane sugar so that there is an even, brown layer of sugar. Chill for at least 1 hour.