Preheat your oven to 180°C (356°F).
Melt the butter and prepare a working surface for the phyllo pastry.
Take 3 sheets of phyllo pastry and brush a line of melted butter at the top. At the bottom, evenly spread a line of the spinach and cheese filling.
Gently roll the pastry into a long cigar shape.
To start the spiral, tightly but carefully fold the first roll into a mini spiral and place it in the centre of your baking dish.
Repeat the previous step, adding each new roll to the end of the last one, until you’ve completed a large spanakopita spiral. (whatever does not fit, add to another baking dish) - Mine is 36cm in diameter
Brush the top of the spiral with the remaining melted butter.