Transfer the cornstarch and sugar to a small pot and stir to mix. Add the eggs and whisk until fully combined.

Add the milk and salt. Cook over medium heat, whisking constantly, until it starts to bubble. Let it bubble for 1 minute and remove from heat.

Add the chopped white chocolate and vanilla. Let sit for 1 minute. Stir until smooth. If lumpy, blend or strain. Cover with wrap touching the surface and chill.

For the chestnut cream, blend the chestnuts and sweet chestnut spread until smooth. Add water gradually until spreadable.

Dip half of the Savoiardi biscuits briefly in milk. Layer them in glasses. Spread 1 teaspoon of chestnut cream on top of each.

Add half the custard evenly over the chestnut cream in all glasses.

Repeat the biscuit, chestnut, and custard layers. Shape the custard into a gentle peak.

Pipe chestnut cream over each custard mound using a piping bag.

Chill for several hours before serving. Dust with icing sugar and garnish with white chocolate curls.`),

notes:p(`To get the mountain look, shape the custard into a peak before piping the chestnut cream.

For a simplified version, use whipped cream instead of custard.

If omitting white chocolate, triple the sugar and stir in 3 tbsp butter at the end.

Unsweetened chestnut purée can replace chestnuts—use less water.