Place eighteen 3oz (71ml) capacity paper cups on a small baking sheet. Set aside.

In a blender or food processor, add the mangoes, heavy cream, condensed milk, lime juice, saffron threads, and cardamom (if using) and blend until pureed and combined.

Strain the mixture through a sieve into a glass measuring cup with a pour spout and discard any solids.

Divide the mixture evenly among the paper cups, then cover the cups with a sheet of aluminum foil.

Press your hand over the surface of the foil to reveal the circles where the tops of the cups are.

With a sharp knife, poke a small slit in the center of each circle and insert a popsicle stick all the way into the kulfi (the foil helps keep the sticks in place while freezing).

Carefully transfer the kulfi tray to the freezer and freeze for a minimum of 6 hours or up to 4 weeks.

When ready to serve, peel the paper off the kulfi, arrange them on a plate and garnish with crushed pistachios.