01 - In a medium mixing bowl, vigorously whisk cold milk with instant vanilla pudding mix for 2 minutes until fully combined. Allow to rest for 5 minutes until thickened.
02 - Using an electric mixer or whisk in a chilled bowl, beat heavy cream, powdered sugar, and vanilla extract until stiff peaks are achieved. Set aside.
03 - Arrange half of the pound cake cubes in the bottom of a large clear trifle bowl or glass serving bowl to form an even layer.
04 - Spread one-third of the vanilla pudding evenly over the cake cubes, followed by one-third of the whipped cream.
05 - Distribute half of the strawberries and blueberries evenly on top of the whipped cream layer.
06 - Add remaining cake cubes, then layer with another third of the pudding and whipped cream. Arrange remaining raspberries, strawberries, and blueberries on top.
07 - Top with the final portion of pudding and whipped cream, spreading smoothly to cover the fruit.
08 - Garnish the surface with extra fresh berries and optional white chocolate shavings. Refrigerate for at least 2 hours to allow the flavors to meld before serving.