Preheat oven to 350°F (180°C). Grease and line a round baking dish (about 9 inches).
In a bowl, whisk together condensed milk, regular milk, eggs, and vanilla until smooth.
Take one sheet of filo pastry, brush with melted butter, and scrunch it loosely. Place into the dish. Repeat with remaining sheets, arranging in a swirl or spiral pattern.
Pour the custard mixture evenly over the filo.
Bake for 30–35 minutes or until golden and custard is set.
Cool slightly, then dust with icing sugar before serving.