Preheat oven to 350 degree Fahrenheit or 180 degree Celsius.

Chop the chocolates into chunks.melt half and save the other half for later.

Mix the butter and sugar, then beat in the eggs and vanilla essence for 1 to 2 minutes until the mixture becomes fluffy and light in colour.

Whisk in the reserved melted chocolate, then sift in the flour, cocoa powder and salt. Fold the dry ingredients into the wet ingredients.

Finally sold in the chocolate chunks and transfer the batter into a parchment paper-lined square baking

Bake for 20 to 25 minutes and then let it cool down and now it is ready to serve, best with a glass of cold milk.