Preheat the oven to 160˚C.

Grease and line a 20 cm or 8inch loose bottom round cake tin with baking parchment.

Place the chocolate and the butter in a glass bowl set over a saucepan of simmering water over low heat, stirring until smooth. When melted, remove the bowl from the saucepan.

In a second bowl, combine the egg yolk with half of the caster sugar until light and pale texture. Fold in the ground almond, orange peel, orange zest and pistachios then the warm chocolate mixture.

In the meantime, in a third bowl, whisk the egg whites to a soft peak, slowly adding the rest of the caster sugar until a light meringue has formed.

Immediately, fold the egg white meringue very gently in the chocolate mixture.

Pour the batter into the prepared cake tin, smooth over the top and place in the oven.

Bake for 40 minutes or until the top appears dry and a skewer inserted in the middle comes out with a few moist crumbs attached (not a too wet mixture). Don’t overcook so the cake retains moist consistency.

Remove from the oven and let cool completely in the tin.

Decorate with some confit orange slices if desired or simply a dusting of icing sugar.

Serve with some lightly whipped cream.