Sweet semolina filo pie (bougatsa)

Combine the sugar and milk in a medium-size saucepan. Place over a medium heat and bring to a simmer, stirring to dissolve the sugar. Stirring constantly, gradually add the semolina and a pinch of salt and cook for 3 minutes until the mixture thickens. Add 1 tablespoon of butter and the vanilla extract and stir to combine. Pour the mixture into a bowl, cover the surface with baking paper and allow to cool completely.
Preheat oven to 200ºC.
Melt the remaining butter and set aside. Unroll the filo pastry and place between two clean tea towels on the benchtop. Brush a 21 cm round, low-sided cake tin with butter. Brush a sheet of filo with butter and lay it in the tin with the edges overhanging. Repeat with another 9 sheets changing the angle slightly each time as you lay the filo into the tin (this creates an even edge of filo around the tin). Spoon the semolina custard evenly over the filo. Trim 10 sheets of filo into a square just big enough to cover the surface of the tin. Brush each sheet with butter and fan the sheets over the custard to cover the surface. Fold the overhanging edges towards the centre and brush with butter. Place the baking tin in the oven and bake for 25 minutes until golden.
Allow to cool for 10 minutes. Combine the icing sugar and cinnamon and generously dust the surface before cutting into slices.
Serve warm.