In a medium bowl, combine strawberries with 25 gr sugar. In another bowl, combine kiwi with another 25 gr sugar. With the back of a fork, lightly mash the strawberries and kiwis with the sugar so as to release their jucies and then set them aside for about 10 – 15 minutes.
Arrange the sponge cake (cut into small pieces) at the bottom of the baking pan and top them with the strawberries sugar mixture.
In a small bowl, stir cream with a pinch of salt and vanilla essence until they are well combined. Combine the mixture with the mascarpone cheese.
Spread half of the whipped cream and mascarpone cheese over the strawberries.
Arrange the remaining sponge cake on top of the mascarpone cream mixture and then top them with the kiwi sugar mixture. Spread the remaining mascarpone cream on top of the kiwi.
Top the mascarpone cream mixture with black grapes and refrigerate up to 3 hours or more or until the whipped cream is stiff and the sponge cake have softened.