Prepare the pudding mix using package directions, using 2 cups of milk.
Reserve 1/4 cup of the whipped topping. Fold the remaining whipped topping into the pudding mixture.
Layer 1/3 of the cake, 1/3 of the pudding mixture, and the strawberries in a trifle bowl.
Sprinkle the strawberries with sugar.
Repeat the layers, substituting the blackberries and raspberries for the strawberries.
Top with the reserved whipped topping.
Chill before serving. Yields 10 servings.
