• Preheat oven to 170° C (338° F) Fan.

For the syrup:

• Place a pot over medium heat. Add the water, sugar, and orange juice. Bring to a boil and boil for 5 minutes. When ready, set the syrup aside to cool completely.

For the revani cake:

• Put the butter and sugar in a blender bowl and blend for about 1 minute on medium speed using the whisk attachment. The mixture should be light and fluffy.
• While blending, slowly add the egg and orange juice. Blend for 1 minute and then add the flour in batches. Blend until completely combined.
• Grease a 25 x 33 cm (10 x 12 - inch) rectangular baking pan with butter and dust with flour. Add the batter and gently tap on a counter to spread it evenly.
• Bake for 30 minutes, until golden.
• When ready, remove from oven and poke a few holes in the cake with a straight edged knife. Using a ladle, immediately pour the cooled syrup over the cake.
• Allow the cake to soak up the syrup for about 10 minutes. Then cut into pieces and serve.