Ingredients
185g butter, cut into chunks  
185g dark chocolate, broken in pieces 
100g plain flour  
50g cocoa powder 
50g white chocolate, chopped into chunks  
50g milk chocolate, chopped into chunks 
3 large eggs 
250g caster sugar 

Method
Put the butter and dark chocolate into a microwaveable bowl and put into the microwave. Cook on 30 second blasts on high until almost completely melted, being careful not to go too far and cook or burn the chocolate. When just a few lumps remain, mix with a knife and keep mixing, scraping from the bottom until it is one chocolatey smooth bowl of deliciousness.

Preheat the oven to 180c. 

Butter and line a square cake pan 20-23cm. 

Put the flour and cocoa powder into a small bowl and mix together with a fork or whisk removing any lumps when you do. 

Put the eggs and sugar into a stand mixer and whisk together on medium high until really thick and very pale, think McDonald’s milkshake thickness.  This will take at least 5 minutes. 

Put the chocolate into the egg mixture and very carefully fold through scraping around the edge and through the middle, turning the bowl and scraping the sides as you go to get all stray chocolate mixed through.  You don’t want to knock out the air so do this slowly and carefully.  Stop when the mixture looks more chocolate than not. Carefully add the flour and cocoa powder and incorporate in the same way as before, around the edge of the bowl and through the middle, turning the bowl as you go. You want to just incorporate the flour without over mixing as the air will be knocked out and the brownie heavy. Add the chocolate chunks and carefully stir through. 

Cook for 20 minutes and check - the middle should not wobble and the sides will pull away from the edges when done. If not set, put back in for 10 minutes and check again. In my oven this often takes 40 minutes but ovens vary so much and you do not want it to set and be cake, brownies need that gooey centre.

Leave in the tin to cool. If you can that is.

- Recipe adapted from BBC Good Food