Gianduja Madeleines

The addition of rich, creamy hazelnut-flavored gianduja chocolate not only imparts a wonderful flavor to these madeleines, it also contributes to their moist texture. It is crucial that the hazelnuts are ground very finely. If you do not have finely ground nuts on hand, grind them in a food processor together with about one-third of the granulated sugar from the recipe to prevent the nuts from caking and forming a paste. The remaining sugar will still be sufficient to whip the meringue.