Line a 20cm springform tin with baking parchment.
Mix crushed digestive biscuits with melted butter.
Press firmly into the tin and chill for 20–30 minutes.
Beat the cream cheese and icing sugar until smooth.
Add lemon zest, lime zest, lemon juice, lime juice, and vanilla extract.
Whip the double cream to soft peaks.
Fold the whipped cream into the cream cheese mixture.
Spoon the filling onto the chilled biscuit base.
Smooth the top with a spatula.
Refrigerate for at least 4 hours or overnight.
Decorate with whipped cream, lemon slices, lime slices, fresh berries, and extra zest before serving.