Combine all the ingredients except the custard apple pulp and mix well till the sugar dissolves. Add the custard apple pulp and mix well.
Pour into a shallow container. Cover and freeze till it is semi-set.
Divide the mixture into 2 batches and churn in a blender till the ice crystals break and the ice-cream is smooth and creamy.
Transfer both the batches into the shallow container. Cover and freeze till firm. 5 to 6 hours.
Add chocolate syrup and serve
