Sieve together both the flours, baking powder and salt.
In a bowl, combine butter and sugar. Whisk with hand blender or your own hands to make a smooth creamy mixture.
Now add the eggs to the mixture and combine well.
Add vanilla essence, orange zest and orange juice and combine well.
Fold in the dry ingredients little by little, alternating with milk.
Pour batter into the greased and floured pan (I used a loaf pan).
Bake in preheated oven at 170C for 30 - 35 mts (I left it for 35 and I think it was over done. I would have loved switch off the oven after 30 minutes. Also, I used a non stick dark pan. If you are using a tin baking pan, increase the temp to 180C) or till a toothpick inserted into the cake comes out clean.
Let it cool completely before taking it out, slice and eat if you have really lasted that long :)