*How much sugar you will need depends on the sweetness of the yogurt and chocolate. I used dark chocolate and unsweetened vanilla yogurt, so I added 1 tablespoon of sugar. If you use already sweetened yogurt and a sweeter chocolate, you may need to add less sugar, or even none at all if you decide that it's sweet enough. I highly recommend tasting the mousse when you make it to decide how much sugar you want to add