In a saucepan, warm ⅓ cup of Vin Santo with half of 2 tablespoons of sugar just until the sugar melts, keeping the wine below 95°F / 35°C.
In a heatproof bowl, whisk 90g of egg yolks with the remaining sugar until smooth. Whisk in a ladle of the warm wine, then the rest.
Set the bowl over a pan of simmering water. Whisk constantly until the cream has grown in volume and reaches 180°F / 82°C, or until the whisk leaves furrows.
Set the bowl over a bowl of ice and stir gently for 2 minutes to cool.
