01 - In a medium bowl, gently combine strawberries, blueberries, raspberries, and granulated sugar if using. Allow berries to macerate for 10 minutes to release their juices.
02 - In a large mixing bowl, whip heavy cream to soft peaks using an electric mixer or whisk. Add softened mascarpone or cream cheese, granulated sugar, and vanilla extract; whip until smooth and thick.
03 - If making custard from scratch, follow your preferred recipe and allow to cool. Use chilled custard or ready-made vanilla pudding.
04 - Arrange half of the cubed pound cake or sponge cake in the bottom of a trifle bowl or individual serving glasses.
05 - Spoon half of the berry mixture, including juices, over the cake layer.
06 - Evenly spread half of the vanilla custard over the berries, followed by half of the prepared vanilla cream.
07 - Repeat the layering process with the remaining cake cubes, berries, custard, and vanilla cream for a second layer.
08 - Garnish with fresh mint leaves and extra berries if desired. Cover and chill for at least 1 hour to allow flavors to meld before serving.