Take a mixing bowl and a strainer. Add all the dry ingredients together except sugar and strain it for twice. Add sugar to it.
Then add all the wet ingredients to the same bowl and mix properly. Add chopped walnuts and choco chips to it.
Grease a baking tin and dust it with maida. Pour the batter to the baking pan and tap on the kitchen platform to release air.
Preheat the oven on 180degree celcius for 10mins. Then put the tin in the oven and bake for 25 to 30 minns or the tooth pick comes clear. Bring out and keep on the wire rack to cool down to room temperature.
using jaggery then first grate the jaggery properly. Don't add jaggery to the dry ingredients. Take another bowl add all the wet ingredients and mix. Then add jaggery to it and mix again upto jaggery melted in the wet ingredients. Then repeat the above steps
Serve the brownie either with whipped cream or ice cream