Preparation
Combine all ingredients using an electric mixer. Mix on low speed for 2 minutes then on medium speed for another 2 minutes, or until mixture becomes smooth.
Pour mixture into a shallow 21cmx32cm greased baking cake tin and line the base with baking paper. Bake in a 180°C preheated oven for 20-25 minutes or until the cake is firm to the touch when pressed with a finger.
Remove from the tin and keep the cake top side up on wire rack until it cools.
Place hazelnut chocolate paste in a bowl over hot water until it melts.
Spread this topping over the cold cake and sprinkle crushed hazelnut over. Cut into squares and serve.