Arrange half of the cake cubes in the bottom of a large glass trifle bowl to create an even base layer.

Drizzle half of the orange juice or sherry over the cake layer to moisten.

Distribute half of the strawberries, blueberries, and raspberries evenly over the cake cubes.

Spread half of the vanilla custard over the berry layer using a spatula to ensure it reaches the edges of the bowl.

Repeat the layers with the remaining cake cubes, juice, berries, and custard.

In a separate chilled bowl, beat the heavy cream, sugar, and vanilla extract until stiff peaks form.

Spoon the whipped cream over the final custard layer and smooth the surface or create decorative peaks.

Cover the bowl with plastic wrap and refrigerate for at least 4 hours to allow the cake to absorb the flavors and the layers to set.

Garnish with additional berries and fresh mint leaves immediately before serving.