1. Firstly preheat the oven to 180°C/350°F/gas 4. Grease and line a small square brownie tin (around 15cm by 15 cm) with parchment paper.
2. In a bowl mix together the butter and sugars until it is blended well and fluffy.
3. Slowly beat in the eggs, a little at a time, making sure it is well incorporated after each addition.
4. Fold in the melted chocolate and stir in the nuts and orange zest (if using).
5. Sift over the flour, baking powder, salt and cocoa powder and mix well.
6. Pour into the lined brownie tin and smooth over before baking in the oven for 20 – 30 minutes. You can test to see if it is cooked by inserting a skewer into the centre. It should come out with a little mixture stuck on. This means it will be a little gooey which is perfect.
7. Leave to cool in the tin for 45 minutes before carefully removing it and slicing into pieces.
Anjali’s Tip If they are too crumbly when you cut them just pop them in the fridge to firm up first