Break passion fruits in half, and empty contents into a bowl. Use a little water to help rinse the juice out of the skins. Mix with hands to soften pulp. Strain through a sieve or cheesecloth. Stir in sugar and sweetened condensed milk.

In a chilled bowl, beat cream until stiff peaks form. Fold 1/3 of the cream into the passion fruit mixture, then quickly fold in remaining cream until no streaks remain.