1In medium bowl, beat pudding mix, vanilla, milk and sour cream with electric mixer on medium speed until soft pudding forms. Cover; refrigerate.
2In trifle bowl or large clear bowl, arrange 1 layer of sliced cake to cover entire bottom of bowl. Top with a layer of pudding, then a layer of whipped topping, and then a layer of strawberries. Repeat all layers except use blueberries. Continue with layers until bowl is full.
3Cover with plastic wrap; refrigerate until ready to serve.