Reserve one cup of milk and pour the rest of the milk with the sugar in a heavy based saucepan and bring just to boil to melt the sugar. Turn off the heat. In a large bowl pour the reserved milk, whisk in the cornflour to dissolve, then add in the eggs, the vanilla and the pinch of salt. Whisk well to combine.

With a ladle, pour in some of the hot milk in the cornflour mixture to temper it whisking constantly. Use almost half of the hot milk in the cornflour mixture then tip the cream back into the pan with the milk.

Over low heat and with patience, stir continuously with the whisk until the cream thickens. Turn off the heat, add the butter and whisk well to combine. Cover the surface of the cream with cling film and cool in the fridge.

Preheat oven to 180C. Butter the bottom of a round or rectangle baking tray and place half of the fillo pastry, each one buttered and placed on top of each other. Whisk the custard to loosen if it was in the fridge overnight and spread it over the fillo pastry, cover the surface with the rest of the fillo pastry, buttering each one again and seal the edges.

Brush the surface with butter again and bake until golden brown. Serve warm with a dusting of icing sugar and ground cinnamon.