Preheat your convection oven to 180º C, in a fan-assisted setting.

Separate the egg whites from the yolks into two bowls.

Butter and line the base of a 22 cm ring-shaped springform pan with parchment paper.

Cut the chocolate and butter into small pieces.

Place them in a bowl for a bain-marie. Let them melt over low heat, stirring occasionally.

Leave the chocolate mixture aside for 5 minutes to cool.

When slightly cooled, add the chestnut cream, rum, orange zest, and egg yolks.

Mix with a whisk until the ingredients are well combined.

Place the egg whites with salt in a bowl.

Using a hand mixer, beat the whites until stiff peaks form.

Add 2 full tablespoons of meringue (egg white mixture) to the chestnut chocolate mixture.

Gently fold with a spatula until the mixture lightens.

Add the remaining meringue and gently fold until until no white is visible and the merengue is incorporated into the chocolate.

Pour the mixture into the prepared pan and bake for about 30 minutes until set.