Take a bowl and add dry ingredients first.
Add wheat flour, baking powder, baking soda, corn flour and sift well.
Sift thrice or four times so that the dry ingredients are mixed well also it results in soft fluffy cake. Keep it aside.
Take another bowl and add all the wet ingredients one by one.
Add oil, orange juice, sugar, vanilla essence. Mix well and keep aside.
At this stage you can also add orange zest if you are going to add it. It really gives good flavour to the cake.
To the wet ingredients, add the dry ingredients. We can add by sifting.
Mix it by cut and fold method. Donot mix vigorously.
After mixing divide it into two portions.
In one portion, add cocoa powder and mix well.
Now grease the pan in which you are going to bake. Add one layer of plain orange cake batter, then chocolate orange cake batter, then plain orange cake batter.
Pre-heat the oven at 180 degree celsius for 2 to 3 minutes.
Bake at 180 degree celsius for 35 minutes. The temperature and time vary from oven to oven.
Insert the toothpick to check if the cake is done. Once it comes out clean, remove from the oven.
Allow it to cool and remove from the mould. When cut lengthwise, you can see the layer.
Serve it hot with tea.