Combine first 6 ingredients in a bowl. Brush a sheet of filo pastry lightly with butter. Top with another sheet and brush again. Repeat process until all sheets are used. Place layered filo sheets on a large non-stick baking tray. Spoon pear mixture, shaping it into a long, narrow rectangle, in the middle of the bottom third of the pastry. Fold over - about 2-3 inches on either side - the sides of the pastry and then carefully roll filling into the pastry. Brush top with a little butter. Make small cuts, about 2 inches apart, into the top of the pastry to make cutting easier after baking. Bake in the middle of an oven preheated to 375 degrees F for 25-30 min, until puffed and golden. Let rest 10-15 minutes before slicing with a sharp, serrated knife. Dust portions with icing sugar and, if desired, serve with a dollop of whipped cream.