Cut the cream cheese into cubes and leave it on the counter to soften. In a 1.5-liter / 6-cup mixing bowl, stir the graham crumbs, sugar and melted butter until the mixture looks like wet sand.

Divide the crumbs among six 200 ml / 7 oz glasses, about 3 tbsp each. Press down firmly with the back of a spoon into a flat layer about 1 cm / 1/2 inch thick. Freeze for 10 minutes while you make the filling.

In a 3-liter / 3-quart bowl, beat the softened cream cheese, powdered sugar, vanilla, lime zest, lime juice and salt with a hand mixer on medium for 2 minutes until smooth. If you spot small white lumps, the cream cheese was too cold. Microwave the bowl for 5 seconds and beat again.

Wipe out the 1.5-liter bowl and whip the cold heavy cream on medium-high for 2 to 3 minutes, until stiff peaks hold when you lift the beaters. Fold one third into the cream cheese mixture with a spatula to loosen it, then fold in the rest gently until no streaks remain.

Spoon about 100 ml / 7 tbsp of filling over each base, leaving about 1 cm / 1/2 inch below the rim, and smooth the tops. Wipe the rims clean, cover with plastic wrap and chill for 4 hours, until the filling is set and holds its shape when pressed with a spoon.

Halve the finger limes crosswise and squeeze from the cut end so the pearls push out onto a plate. Within 30 minutes of serving, spoon about 1 1/2 tsp of pearls over each cup.