• Preheat the oven to 180C/350F degrees.
• Grease and line an 8 inch spring form cake pan with parchment paper.
  
• Melt the butter and chocolate together in a bowl over simmering water (Bain Marie). Or you could zap it in the microwave.
  
• In a bowl, whisk the egg yolks together with the vanilla.
• Add the chocolate mixture, then add the hazelnut flour, salt and the monk fruit sweetener.
• In another bowl, whisk the egg whites to stiff peaks with an electric whisk.
• Add ¼ of the egg white mixture to the chocolate mixture and fold in gently.
• Fold the remaining egg whites into the mixture.
  
• Pour into the cake tin and bake for 35 to 40 minutes until firm.
• Cool in the tin for 5 minutes, then remove from the cake tin and cool on a wire rack.

Make the ganache

• Place the chocolate chips in a medium mixing bowl.
• Heat the cream in a pan on a medium heat until it is just simmering.
• Remove from the heat and pour over the chocolate and let sit for 2 minutes.
• Stir until you have a smooth mixture.
• Spoon or pour over the chocolate hazelnut ganache and chill in the fridge until ready to serve.