For the praline
Heat the sugar in a broad non-stick pan and cook on a medium flame for 5 to7 minutes or till the sugar melts, while stirring continuously.Remove from the flame, add the cashewnuts and butter and mix well.

Spread the mixture on a greased flat surface and allow it to cool and harden.Scrape it out using a palate knife and coarsely powder it using a mortar-pestle (khalbatta). Keep aside.

For the ice-cream
Combine all the ingredients except the butterscotch essence and whisk together so that no lumps remain.

Bring to a boil in a non-stick pan and simmer for 7 minutes, while stirring continuously.Cool completely, add the butterscotch essence and mix well.

Pour the mixture into a shallow aluminium container. Cover with an aluminium foil and freeze for 6 hours or till semi-set.Remove the semi-set ice-cream from the freezer and transfer it in a mixer and blend till smooth.