Firstly, pre-heat the oven to 350F/180C.
Generously butter two 8 1/2 x 4 1/2 x 2 1/2-inch loaf pans and lightly dust flour over them. Line the bottom of the greased and dusted pans with parchment paper.
Cream together 2 cups of sugar and 2 sticks of butter in the bowl of an electric mixer fitted with a paddle attachment for about five minutes, or until the mixture is light and fluffy.
Set the mixer to medium speed and beat in 4 large eggs, one at a time, beating well after putting in each egg. Also add the grated orange zest.
Then in a large bowl sift together the dry ingredients - flour, baking powder, baking soda and salt.
In another mixing bowl, combine the wet ingredients - buttermilk, 1/4 cup of orange juice and vanilla essence.
Now add the dry and wet mixtures alternately to the prepared batter, starting and finishing with the dry mixture, mixing lightly after each addition till you get a smooth batter.
Now pour the cake batter into the greased pans and smooth the tops.
Pop the pans into the oven and bake for 45 to 60 minutes, until a cake tester inserted into the cake comes out clean.
Meanwhile, in a small saucepan, heat the remaining half cup sugar and the remaining half cup orange juice over low heat until the sugar completely dissolves.
Once the cakes are done allow them to cool in their pans for ten minutes.
Then remove the cakes from the pans and set them on a baking rack placed over a tray.
Pour the orange syrup all over the cakes and allow them to cool down completely. The orange syrup really lifts the flavour and makes the cake nice and moist.
Finally, to glaze, mix the confectioners' sugar and fresh orange juice in a mixing bowl, blending with a wire whisk until nice and smooth. If required, add a couple more drops of orange juice, to make it easy to pour.
Now drizzle the prepared glaze over the top of one cake. Allow the glaze to dry completely.
Cut delicious Orange Cake into slices and serve.
Wrap the second cake well and store in the refrigerator upto 2-3 days.