1.    Heat oven to 325°F.

2.    Put orange slices in bottom of an 8" x 8" baking dish; pour 1 cup orange juice over top.

3.    Cover baking dish with foil.

4.    Bake until oranges are very soft, 40–45 minutes.

5.    Transfer to a rack to cool.

6.    Meanwhile, bring ¾ cup sugar, cinnamon, and 1½ cups water to a boil in a 2-qt. saucepan.

7.    Cook for 5 minutes; remove from heat.

8.    Pour syrup over orange slices.

9.    Let cool completely. 

10. Grease a 9" x 13" baking dish and dust with flour.

11. Set aside.

12. Combine remaining sugar and eggs in a bowl.

13. Beat with a hand mixer until pale and thick.

14. Whisk in remaining orange juice, oil, yogurt, zest, and vanilla.

15. In a separate bowl, whisk together semolina and baking powder.

16. Whisk into egg mixture.

17. Then stir in phyllo.

18. Pour mixture into prepared dish.

19. Bake until lightly browned, 35–40 minutes.

20. Pour syrup evenly over cake.

21. Let cool.

22. Cut cake into 12 squares and cut orange slices into quarters.

23. Top each square with an orange quarter.