In a large bowl combine the yoghurt, whipped cream, creme fraiche, berries and marshmallows. Fold the mixture gently especially if you are using very ripe berries as you don't want them to just become berry mush.
Spoon into individual servings, wine glasses are always an easy option that look stylish too, or arrange the mix in one large serving dish if you prefer. Chill for at least a couple of hours and then serve. Really simple but tasty dessert that can be made in advance.
This is an extremely versatile recipe as it can be made with all kinds of different fruits and sweet treats.