In a small chilled metal bowl whisk heavy cream in a figure eight motion. Just as soft peaks are forming, add the granulated sugar gradually. Continue whipping the cream until stiff peaks form.
Cover the bowl and chill in an ice bath. Combine room temperature mascarpone and cream cheese with a rubber scraper. Add vanilla and powdered sugar. When cheese mixture reaches a smooth consistency, set aside, keeping the mixture at room temperature. Just before serving , lightly fold whipped cream into the cheese mixture.