Once the apple has cooled completely you can start to make the pie cases.
Use some of the melted butter and grease the insides of the muffin cups. Put aside.
Remove the filo pastry from the packaging, unroll and lay the pastry flat on the bench. Cover with a damp tea towel, this will prevent the pastry from drying out as you work.
For each pie case you will need, four pieces of filo pastry about 27 cm x 23 cm. <-- Note 2
Lay one rectangle piece of pastry flat on the bench, use a pastry brush and dot the surface of the pastry with melted butter. Place a second sheet of pastry on top to create a cross and dot the surface with butter. Angle a third sheet of pastry over the second, dot with butter, then finish with a fourth sheet of pastry.
Gently lift the pastry and line the inside of one of the muffin holes. Gently, ease and press the pastry to the sides and base of the tin. Evenly scrunch the overlapping pastry into a circle around the muffin cup opening.
Repeat steps 5 and 6 and make the pastry cases for the remaining muffin cups.