In the bowl of an electric mixer fitted with the whisk attachment or large bowl with handheld electric mixer mix together the first 3 cups of heavy cream and powdered sugar until stiff peaks form.
Divide into three equal parts. Fold in milk chocolate into one part, dark chocolate into second whipped cream and the white chocolate into the last bit of whipped cream.
Place the first layer of chocolate cake, spread with white chocolate whipped cream, place next cake layer followed by milk chocolate whipped cream then a chocolate cake layer then the dark chocolate whipped cream then a chocolate cake layer.
Spread chocolate ganache on top and let drizzle down the sides. Place fresh berries on top while the ganache is still wet, so the berries stick into place.