Pre-heat the oven to 180°C (350°F) and prepare a cake tin (I used a rectangular one, slightly larger than 8" x 8").
Melt the chocolate and then set to one side.
Using a mixer or electric whisk, beat the sugar and butter until light and fluffy.
Add in the eggs one at a time followed by the melted chocolate and vanilla.
In a separate bowl, mix the dry ingredients together.
Alternating the dry ingredients with the milk, add to the wet ingredients and work until the batter is nice and smooth.
Bake for around 25-30 minutes until an inserted skewer or toothpick comes out clean. Leave to cool in the pan.