Combine milk and cornflour in a heavy pan. Blend in beaten eggs and add salt and sugar. Place over medium heat and stir constantly until thickened and bubbling. Remove from heat, stir in vanilla essence and cover top of custard with buttered paper to prevent a skin forming.
Place kataifi in a large bowl and gently separate strands with fingers. Grease a 20x28 cm (8x11 inch) oven dish with some of the butter. Put half the kataifi in the base, pressing it down to make it compact. Drizzle 1/4 cup butter evenly over it. Pour custard filling over kataifi, spreading it evenly. Top with remaining kataifi. Spread evenly and pat down gently. Pour remaining melted butter evenly over top.
Bake in a 375 degree (moderately hot) preheated oven for 45 minutes until golden brown. Remove from oven and leave until cool.
Dissolve sugar in water over medium heat, add lemon rind and cinnamon bark and bring to the boil. Add lemon juice and boil over medium heat for 15 minutes, skimming when necessary. Do not stir once syrup is boiling. Strain hot syrup over cooled pastry. Leave until cold and cut into diamond shapes to serve.
Note: The previous recipe is the traditional way in which this dessert is made. As the custard and syrup soften the kataifi, many good cooks use the following method for a crisp finish:
Prepare the syrup as directed above and leave until cool. Place the kataifi in a bowl and loosen stands. Pour on 1/2 cup melted, unsalted butter and mix with fingers to coat strands. Spread kataifi in two buttered 20x28 cm (8x11 inch) straight-sided oven dishes and press down to make it compact. Bake in a moderately hot oven for 20-25 minutes until golden take care that it does not become too brown. Remove from the oven and pour cooled syrup evenly over hot kataifi in each dish. Cover each dish with a tea towel so that kataifi softens slightly, otherwise it will be difficult to cut.
Make custard as directed in previous recipe and pour while hot onto kataifi in one dish. Invert other dish of kataifi on top of the custard. Leave uncovered until cool, then cut into diamond shapes to serve.