Step 1

Preheat oven to 180C. Spread hazelnuts over a baking tray. Bake for 10 minutes or until toasted. Place hazelnuts in a clean tea towel and rub to remove the skins. Coarsely chop.

Step 2

Reduce oven to 160C. Grease and line the base and sides of two 20cm (base measurement) springform pans. Combine hazelnut, chocolate and 2 tbs of caster sugar in a small bowl.

Step 3

Use an electric beater to whisk the egg whites in a clean, dry bowl until firm peaks form. Gradually whisk in the remaining caster sugar, 1 tbs at a time. Whisk until sugar dissolves. Add the hazelnut mixture and use a metal spoon to gently fold until just combined.

Step 4

Spoon the mixture evenly among the prepared pans. Smooth the surface. Bake for 30 minutes or until crisp and dry. Set aside in pan to cool.

Step 5

Combine the mascarpone, cream, icing sugar and the cocoa powder in a bowl.

Step 6

Carefully turn one of the cakes onto a platter. Spoon the mascarpone mixture over top of the cake. Top with the remaining cake. Dust with the extra cocoa powder.