Step 1

Preheat oven to 180C/160C fan forced. Grease a square 20cm (base measurement) cake pan and line with baking paper.

Step 2

Whisk the flour, sugar, cocoa powder and baking powder in a bowl until combined. Make a well in the centre. Add the oil, vinegar and 330ml (1 1/3 cups) water. Slowly whisk until a smooth batter forms. Pour into the prepared pan. Bake for 17 minutes or until a skewer inserted in the centre of the cake comes out clean. Set aside in the pan for 5 minutes to cool slightly before transferring to a wire rack to cool completely.

Step 3

Spread the chocolate frosting over the cake and top with assorted chocolate toppings.