Preheat oven to 175°C.

In a bowl combine chocolate and butter and melt it in MW or a double boiler.

Keep it aside.

Add vinegar, vanilla and milk and set it aside for 10 minutes.

In a large bowl, combine together flour, baking powder, cocoa powder and sugar.

Add the milk mix and chocolate mix and whisk to combine.

Use a spatula to fold the batter.

Line a 7"square cake tin with parchment and grease it well.

Let the paper hang outside the tin which will help you to remove the brownies later.

Bake for 35 - 40 minutes until a toothpick comes out clean.

Refrigerate for 2 hours before removing the brownie from the pan.

Trim the sides and slice it into 16 equal squares with a bread knife.

Reheat the slices just before serving.