Cut the fruit into large pieces and put it in a saucepan with 1 tbsp of Dolcedì. Cook over low heat for about 10 minutes. The fruit will melt and begin to thicken. Pass the sauce through a sieve so as to remove all fruit seeds.Add to the mix the yogurt, a little Dolcedì, the vanilla extract and mix well. Leave to set in the freezer at least 4 hours (or overnight).