In a mixing bowl, combine all-purpose flour and salt.
Make a well in the centre and add water, olive oil, and vinegar.
Mix the ingredients until a dough forms.
Transfer the dough to a floured surface and knead for 5-7 minutes.
Shape the dough into a ball, cover it with a towel, and let it rest for 30 minutes.
In a saucepan, heat the milk until simmering.
In a separate bowl, whisk together semolina and sugar.
Gradually add the semolina mixture to the simmering milk, whisking constantly.
Cook for 5-7 minutes until the filling thickens.
Remove from heat and let it cool for a few minutes.
In a small bowl, beat the eggs and vanilla extract.
Gradually add the beaten eggs to the semolina mixture, stirring continuously.
Preheat the oven to 180°C (350°F).
Roll out half of the dough on a floured surface into a thin sheet.
Brush melted butter over the rolled-out dough.
Place it in a greased baking dish, allowing the excess to hang over the edges.
Pour the semolina filling over the dough, spreading it evenly.
Roll out the remaining dough and place it on top of the filling.
Fold and tuck the excess dough inside the dish to seal the top.
Brush melted butter over the top layer.
Place the baking dish in the preheated oven.
Bake for 45-50 minutes, or until the top layer turns golden brown.
Remove from the oven and let it cool for a few minutes.
Dust the top with powdered sugar and sprinkle cinnamon.
Cut into individual servings.