Sift Flour and baking powder,salt n cinnamon powder together for 2 times. Mix sugar and oil/ghee in a mixing bowl till it becomes homogenuous. Add vanilla extract to it.
In a separate bowl, beat eggs for around 15 minutes. Add this mixture to sugar and oil/ghee n mix lightly.
Divide all purpose flour in 3 parts and mix them one by one. Mix it well. Add walnuts and mix well. Keep aside few walnuts for decoration.
Pour this mixture in a greased bread / cake pan. Decorate it with the remaining walnuts. Preheat oven at 375 degrees for 15 minutes.
Bake the cake for 45 minutes depending on your oven. Cake is ready when toothpick inserted in it comes out clean.
Remove the pan from oven and keep it for 10 minutes. Then remove the cake from pan on a grill. Cut the cake after 5 minutes.