Butter Free Orange and Rosemary Cake

Made in a 13.5 x 8" tray bake (20 squares):

Juice and zest of 1 orange
Zest of 1 lemon
2 tbsp rosemary leaves (fresh is better, but dried is fine)
250g Greek yogurt
125ml olive oil
200g sugar
2 eggs
1 tsp vanilla extract
275g plain flour
1 tsp bicarbonate of soda
1 tsp baking powder
1) Whisk the egg and sugar in a bowl, followed by the orange juice and zest.
2) Sift the flour, baking powder and bicarbonate of soda into a separate mixing bowl.
3) Fold in the orange mixture, then mix in the yogurt and oil until well combined.
4) Stir in the rosemary then pour into a lined tray.
5) Smooth over with a knife, then sprinkle over the lemon zest evenly.
6) Bake at 180 degrees C for 30-35 minutes until you can pull out a toothpick clean.