Preheat oven to 190 C / Gas 5. Arrange pastry in a 23cm pie dish and refrigerate while preparing filling.
Beat butter, caster sugar, brown sugar, flour, nutmeg, allspice, salt and cinnamon together in a bowl using an electric mixer until smooth. Beat eggs, 1 at a time, into butter mixture until incorporated; fold in pears. Pour filling into chilled pastry case.
Bake in the preheated oven until filling is set in the middle, 30 to 35 minutes. Cool completely before serving, about 1 hour.
I used all brown sugar, Demerara instead of soft brown as that's what I had on hand. Also it took a lot longer to bake than the recipe stated but it tastes very good! Level of spice just right, nice and sweet but not too much. If I make it again I may add some flaked almonds on top for a bit of crunch. - 23 Nov 2016