In a bowl take buttermilk,sugar,butter,vanilla extract and mix well. In another bowl sieve whole wheat flour,baking powder,baking soda,salt and cinnamon for twice.add this in buttermilk mixture and gently fold to make a smooth batter.

Add chopped walnut into the batter and mix with cut and fold method.

Pre heat oven @180 degree for 10 minutes. Pour the batter into the greased pan and tap 2-3 times to release the air bubbles. Bake for 30-35 minutes or until a tooth pick inserted comes out clean.

Remove from oven and cool down. cut into pieces and serve.