Step 1

Preheat the oven to 180°C (350°F) (without fan).

Step 2

Line a 23 cm (9 inch) square baking tin with baking paper.

Step 3

Melt 200 g (7 oz) of the chocolate in a bain-marie and set aside to cool slightly.

Step 4

Chop the remaining chocolate into small chunks.

Step 5

Beat the sugar and butter together until it is pale and fluffy. I like to do this with an electric stand mixer.

Step 6

Sift the flour, cocoa powder, baking powder and salt into a medium bowl.

Step 7

Add the eggs one at a time, together with a tablespoon of the dry ingredients.

Step 8

Beat in the melted chocolate.

Step 9

Fold in the remaining dry ingredients and the chopped chocolate pieces.

Step 10

Pour the mixture into the baking tin and smooth out the batter with an off-set spatula.

Step 11

Bake for about 30 to 35 minutes. A skewer inserted in the middle of the cake should come out sticky but not with raw cake mixture attached to it. The cake will also continue to cook as it cools.

Step 12

Leave the cake to cool on a wire rack before slicing.