Bake in a shallow 40×26 cm baking pan, buttered or oiled. Preheat the oven at 160°C in air, or at 180°C with extra heat on the bottom rack.
Spread the filo pastry and cut it in small pieces. Leave them aside for 10 min to dry.
Mix in a bowl the oil, sugar, eggs, orange zest, creme fraiche, orange jam, baking powder, yoghurt and as much vanilla as you wish.
If you have time, leave the sugar to rest in the liquids. In this way, it will melt more properly and will caramelize better during baking. Stir.
Gradually add the broken dry pastry bits to the liquid mixture, making sure they get juicy all over. This is necessary, otherwise the bits will stick between them, forming a ball, and will not bake properly or absorb the syrup.
Keep gradually adding the pastry bits, until they form a uniform mass, like a cake mush, but without containing balls made of bits stuck together. If such balls form, break them apart. Let the mixture stand for 10 min, so that the pastry bits absorb the liquids.
Pour it in a thin layer into a baking pan, oiled with olive oil, and bake for approx. 30 min, until the surface becomes solid and slightly golden brown, forming a thin crust. Take out the pie and gradually spread the cold syrup all over, while still hot. Let it cool down and absorb the syrup.
The same as all syrupy desserts, let it cool down completely and get juicy, and then cut it in pieces.