Chopped chocolate, put it in a microwave safe bowl and melt it in a microwave.

Once chocolate gets little melted then put butter and melt till you get smooth consistency.

Now in another bowl mix all the dry ingredients, all purpose flour, baking powder and sugar and mix it well. Now put all the dry ingredients into the melted chocolate and mix it well.

Now add milk, vanilla essence and chopped wallnut and mix well using cut and fold mothed the batter becomes smooth.

Now take square dish and grease it with oil. Now pour the brownie mixture in to the greased dish and tap a little so that evenly spread. Or you can level it with a spatula.

Pre heat oven to 180 degrees for 10 minutes. Now brownie bake at 180 degrees for 25mins or till it done. Take out the cake dish from the oven and let it come at room temperature. Now cut in to the pieces.

For chocolate sauce, melt chocolate. Now mix little cream and mix well. Now add all the cream and take a smooth consistency and chocolate sauce is ready.