Preheat the oven to 180 C / Gas 4. Grease a 23cm round tin or line with baking parchment.
In a small bowl, whisk the egg yolks with 60g sugar until pale. In a separate bowl, whisk the egg whites until stiff, you can add a pinch of salt to help things along. Carefully fold the whites into the yolk mixture. Sift flour directly into the mixture and fold in carefully.
Pour the cake mixture evenly into the prepared tin.
Bake for 10 minutes, until golden. Remove the parchment and place cake on a cooling rack.
Whisk 200ml of the chilled cream until stiff peaks have formed. Fold in the melted chocolate.
Place the cake layer into the bottom of a springform tin and carefully spread the chocolate mousse over the top. Chill in fridge.
Soak gelatine in some cold water and let stand for 15 minutes.
Drain the syrup from the pears and in a blender, mix the pears with 50g sugar. In a small saucepan, warm up the pears on low heat, drain gelatine water and add gelatine to the warm pear mixture. Blend to dissolve gelatine. Let cool.
Whisk the remaining cream until stiff. Gradually add to the pear mixture and whisk until light and fluffy.
Over the chocolate layer, spread the pear and cream mixture and chill in the fridge for at least 12 hours.
To serve, decorate with chocolate shavings.
You can substitute 1 tablespoon of powdered gelatine for the 2 sheets and dissolve in 100ml water.
Room temperature egg yolks and egg whites will be easier to whisk.