Nigella's brownie (Self Adapted)

Ingredients

375 g soft unsalted butter ( I used salted hence didnt add salt later and i felt butter was too much so even 300 g would be good enough)

375 g best quality dark chocolate ( I used 160 grams dark chocolate and rest good quality milk chocolate- one can make from plain milk chocolate too)
6 large eggs
1 tablespoon vanila extract
500 g caster sugar ( its generally 21/4 cups but i used 2 cups plain sugar and blended it in mixer and used 2 3/4 cups of caster sugar and so sweetness was perfect)
225 g plain flour (2 cups)
1 teaspoon salt ( i didnt use)
300 g chopped walnuts ( i used 1 cup due to less at home but 2 cups will be amazing)

Directions:

1. 1 Preheat the oven to 180°C.
2. 2 Line your approximatley 33 x 23 x 5 1/2cm brownie pan with foil or baking paper. ( i used a 9" springform but usual pan is recommended due to leaks)
3. 3 Melt the butter and chocolate together in a large heavy based saucepan.
4. 4 In a bowl beat the eggs with the sugar and vanilla.
5. 5 Measure the flour into another bowl and add the salt.
6. 6 When the chocolate mixture has melted, let it cool a bit before beating in the eggs and sugar mixture, and then the nuts and flour.
7. 7 Beat to combine and then scrape out of the saucepan into the lined brownie pan.
8. 8 Bake for about 25 minutes ( it usually takes 45 minutes to a hour).
9. 9 When its's ready, the top should be dried to a paler brown speckle, but the middle still dark and dense and gooey.
10. 10 Keep checking the brownies as they cook; remember that they will continue to cook as they cool.
11. 
    
12. Note: my brownie took long to cook and i did mistake to leave overnight in oven and so was hard by morning. But it was perfect in gooeyness. So cook it maximum for an hour and take it off, cool it and leave in fridge overnight so it cooks perfectly.