In a mixing bowl, crush the digestive biscuits until fine crumbs form. Mix in the melted butter until well combined.
Transfer the mixture to a 9x9 inch baking pan, pressing down firmly to create an even layer at the bottom. Refrigerate while you prepare the filling.
In a separate bowl, combine the softened cream cheese, powdered sugar, heavy cream, brewed coffee, and vanilla extract. Use an electric mixer to beat until smooth and fluffy.
Pour the coffee mixture over the chilled base and spread evenly using a rubber spatula.
Cover the pan with plastic wrap and refrigerate for at least 2 hours or until set.
Once set, remove from the refrigerator and top with fresh mixed berries and chocolate shavings if desired. Cut into bars and serve chilled.
