PREHEAT oven to 400° F.
BAKE potatoes for 50 to 60 minutes or until soft. Cool for 10 minutes; cut in half lengthwise. Scoop out insides with a spoon being careful not to break the skins.
COMBINE potato pulp, pesto and sour cream in medium bowl. Whip until blended. Spoon mixture back into potato skins. Top with cheese and pancetta.
BAKE for an additional 15 minutes or until cheese has melted and potatoes are hot.