Dark chocolate and nut brownie

Method

1. Preheat the oven to 165°C. Spray a 28 x 13 x 6.5 cm loaf tin with canola oil and line with a strip of baking paper to cover the length of the tin plus overlap of a couple of centimetres either side. Spray the paper with oil.
2. Whisk the eggs and sugar in a freestanding electric mixer on medium speed for 10 minutes or until the mixture is thick and has doubled in volume. Reduce the speed to low and continue to mix.
3. Place 300 g of the dark chocolate and all the butter in a bowl and melt together either in a microwave or over a double boiler.
4. Sift the flour, cocoa powder and salt into the chocolate mixture and mix well with a spatula. Add this mixture to the egg mixture in the electric mixer, with the mixer running on low. Mix well for 30 seconds. Remove the bowl from the machine and fold in the nuts, remaining chopped dark chocolate and the milk chocolate, using a rubber spatula.
5. Pour the mixture into the prepared tin and gently tap to level. Bake for 45 minutes or until a light crust has formed on top. The brownie needs to be underbaked to ensure its fudginess. It should still be a bit gooey when tested with a skewer.
6. Remove the pan from the oven and allow the brownie to cool in the tin for 20 minutes before turning it out onto a wire rack to cool completely. Wrap the brownie in plastic wrap while still warm to keep it moist, and store in the refrigerator overnight, or serve immediately.
7. To make the chocolate sauce (if desired), place the cream, milk and sugar in a saucepan over medium heat and bring to the boil. Remove from the heat and stir in the chocolate. Stir to a smooth sauce and serve immediately.
8. Slice and dust the brownie with cocoa powder and serve with ice cream and chocolate sauce, if desired.