In a bowl, combine crème fraîche, whipping cream, and sugar. Cut a vanilla bean in half lengthwise and scrape seeds into crème fraîche mixture (reserve vanilla pod for another use or discard). With a mixer at medium speed, beat mixture until soft peaks form, 2 to 3 minutes. Use at once or cover and chill up to 1 week.
Nutritional analysis per 1/4 cup.