Making the creme fraiche is easy, then the gelatin turns it into mousse. Use this with our Passion Fruit Icebox Cake.
Combine creme fraiche and sugar in electric mixer, and whip to stiff peaks. Don't overwhip or cream will separate.
Pour 2 tablespoons cold water into small bowl; sprinkle with gelatin. Let stand about 5 minutes. Place bowl over a small saucepan of simmering water; stir constantly until gelatin is dissolved and warm to the touch.
Slowly pour gelatin into creme fraiche; whisk. Cover with plastic, refrigerate.
To make creme fraiche, combine 1 cup whipping cream with 2 tablespoons buttermilk. Cover and let stand at room temperature overnight or until thick.