01 - In a medium mixing bowl, vigorously whisk cold milk with instant vanilla pudding mix for 2 minutes. Allow to stand for 5 minutes until thickened.
02 - In a chilled bowl, beat heavy whipping cream with powdered sugar and vanilla extract using an electric mixer or whisk until stiff peaks form. Set aside.
03 - Arrange half of the cake cubes evenly in the base of a large glass trifle bowl.
04 - Spoon one-third of the prepared pudding over the cake layer, followed by one-third of the whipped cream.
05 - Distribute half of the sliced strawberries and blueberries evenly over the cream.
06 - Layer remaining cake cubes, another third of the pudding and whipped cream, and then add raspberries along with any remaining strawberries or blueberries.
07 - Spread the final third of pudding and whipped cream over the top. Garnish with additional berries and optional white chocolate shavings.
08 - Refrigerate for at least 2 hours before serving to allow flavors to meld.