Mix the mascarpone and yoghurt with the vanilla sugar, sugar and lemon zest until smooth.
Roughly chop the couverture and let it melt in a water bath.
Cut the peaches into small cubes and distribute up to 2 tablespoons in dessert glasses. Spread the mascarpone yoghurt cream on top. Place the rest of the peach cubes on top.
Pull the melted couverture over the cream with a spoon.