Add orange zest to 3 tbsp oil, cover and keep aside for 30 min.
Preheat the oven to 180C.
Grease the bundt cake tin generously. Sprinkle flour to all the nooks and corners. Tap off the excess flour.
Add the nolen gur to the orange juice, mix well. Keep aside.
Sift the flour, baking powder, baking soda and salt to aerate the dry mixture. Keep aside.
Take rest of the oil and orange zest oil in a second bowl, add the eggs, one by one, beat well till smooth and fluffy.
Add grated jaggery to 1/2 a cup of orange juice - nolen gur mixture mix till well incorporated. Add this to the egg mix.
Add the dry mixture to the wet batter, mix gently with a rubber spatula. Do not over-mix.
Pour the batter into the greased bundt cake tin, bake at 170C for 35-40 minutes or till a skewer inserted into the center of a cake comes clean.
Allow the cake to cool for an hour, gently loose the edges of the cake and take the cake out gently as in the video.
Turn it upside down, pierce the cake all over with a skewer. Drizzle the remaining orange juice - nolen gur syrup over the cake.
My nolen gur - orange cake is ready to serve.