Prepare the Orange Purée a Few Hours in Advance

1. Wrap the saffron in aluminum foil and lightly toast it in a very hot pan for 1 minute, stirring constantly to prevent burning.
2. Thoroughly rinse the oranges under cold running water and completely dry them with a clean kitchen cloth.
3. Cut 2 and a half oranges into quarters, without peeling, and blend them into a smooth purée using a hand blender.
4. Wrap the remaining half orange with plastic wrap and store it in the refrigerator; we'll use it later for the juice.
5. Add olive purée and half of the toasted saffron strands to the mixture.
6. Blend the purée with the hand blender once more to fully integrate the new ingredients, and store it in the refrigerator until the next day.
7. After a few hours (or the next day), add 150 grams of sugar, 15 ml of sweet wine, and a pinch of salt to the purée, and blend it again with the hand blender until you achieve a very smooth mixture.
8. Preheat the oven to 160ºC for at least 10 minutes to reach the appropriate temperature.
9. In a large bowl, beat the eggs with 150 grams of sugar until they are pale and fluffy.
10. Gently fold the orange purée into the bowl with the beaten eggs and mix until you obtain a homogeneous mixture.
11. In a separate bowl, mix the flour, almond flour, baking powder, and a pinch of salt.
12. Gently fold the flour mixture into the egg and puree mixture using a spatula, making circular motions to retain the air in the batter.
13. Let the batter rest in the refrigerator for about 5 hours so that the baking powder fully rehydrates and works better.
14. Meanwhile, squeeze the reserved half orange to obtain its fresh juice.
15. Bring the orange juice to a boil in a saucepan with 100 grams of sugar, 33 ml of water, and the other half of the saffron threads.
16. Slice another orange into very thin rounds, without peeling it.
17. Reduce the heat to low and submerge the orange rounds in the juice and sugar mixture.
18. Let the rounds cook over very low heat for about 35-40 minutes, until they are tender and caramelized.
19. Remove from the heat and add the remaining 15 ml of sweet wine to the mixture to integrate.
20. Strain the mixture and reserve the caramelized rounds and juice separately in different containers.
21. Line the pan with baking paper, ensuring it overhangs the long sides to facilitate easy removal later, and grease the pan with oil before lightly sugaring it.
22. Fill the pan with the prepared batter and bake it at 180 ºC for approximately 60 minutes, or until the cake is fully cooked.
23. Before removing the cake from the oven, reheat the reserved syrup until it becomes liquid.
24. When you take the cake out of the oven, place the candied orange slices on the surface as decoration, without removing it from the mold.