Beat the cream cheese. Beat the room-temperature cream cheese with the lemon juice, zest, powdered sugar, vanilla, and salt until completely smooth, about a minute. Scrape down the bowl so no lumps remain.
8 oz full-fat cream cheese, room temperature, 2 tbsp lemon juice, freshly squeezed, lemon zest, 2 tbsp powdered sugar, 1 tsp vanilla extract, 1 pinch salt
Melt the white chocolate. Melt the white chocolate gently over a double boiler or in the microwave in short bursts, stirring between each. Let it cool until just warm to the touch.
3 oz white chocolate, chopped
Add the white chocolate. Whisk the warm white chocolate into the cream cheese base until fully combined and glossy. Work quickly so it doesn't set into streaks.
Whip the cream. In a separate bowl, whip the cold heavy cream to medium peaks — it should hold its shape but flop gently at the tip.
1/2 cup cold heavy cream
Fold in the cream. Fold the whipped cream into the base with a spatula until no white streaks remain. The filling should be smooth and pipeable.
Fill the liners. Spoon or pipe the filling over the chilled crusts, dividing it evenly between the 8 liners. Smooth or swirl the tops.
Chill. Refrigerate at least 6 hours, preferably overnight, until the filling is firm enough to un-mold cleanly from the liners.