Preheat the oven to 350F.
Brush a 13x9 oven dish with melted butter.
Take a two sheets of phyllo dough and cover the bottom of the dish, brush with butter.
Working with one sheet at a time, place sheets so they are hanging on the edges of the dish brushing or drizzling with butter in between.
Repeat until you are done with half the sheets.
Spread the custard mixture over the sheets and level with the back of the spoon.
Layer the remaining sheets in the same way keeping three sheets on the side to be used later.
Fold over the hanging sheets from all directions, to enclose the custard layer, brushing in between.
Layer the remaining 3 sheets one at a time brushing in between to cover the top in an even way.
Pour any remaining butter on top.
With a sharp knife score the top of the sheets into squares but do not cut all the way through to the bottom.
Bake for about an hour or until the top is golden brown.
Ladle the cooled syrup on top while it is hot and let it soak the syrup for a couple of hours before serving.