Using the electric beater, whisk the cake preparation with milk, oil and eggs for 2 minutes.
Butter a bundt cake pan, then pour in the preparation. Bake from 45 to 50 minutes, until a toothpick inserted in the center of the cake comes out clean. Remove from oven and leave cool before unmolding in a serving dish.
In a saucepan, boil cream over mild-medium heat. Away from the heat, add the white chocolate. Let it melt, then stir.
In a blender container, mix the sugar with strawberries and raspberries until smooth preparation is obtained. Using a fine sieve, filter the sauce over a bowl.
Garnish the cake with strawberries, raspberries and blueberries. Drizzle with white chocolate sauce and fruit sauce.