Begin by making the gluten-free shortcrust pastry recipe over here to create a sweetened 23cm (9") tart case. Follow the instructions for making the dough and blind baking a 23cm tart case, including the baking time without the baking beans. Once your pastry case is blind baked, come back here to make the filling. Reduce the oven to 180C / 160C fan.
For the filling, mix the eggs, pumpkin puree, light brown sugar, vanilla extract, cornflour, spices and double cream together in a large mixing bowl until evenly combined. The cream should be added without whipping it first.
Carefully pour the filling into the warm, blind-baked pastry case. Place the tin on a baking tray.
Bake at 180C/160C fan for 50-55 minutes. The edges of the filling should be set, with a slight wobble in the centre when you gently move the tin. If the centre still ripples like liquid, continue baking and check again. Don't wait until the middle is completely rigid, as the filling will firm up further as it cools.
Remove from the oven and leave to cool in the tin on a cooling rack, then refrigerate within 2 hours of baking. Chill until completely cold and the filling has firmed up before carefully removing from the tin and slicing. Serve with cream or whipped cream, if you like.
Optional pastry decorations: Cut shapes from your pastry offcuts using biscuit cutters. Place on a baking tray lined with non-stick baking paper and bake separately at 180C/160C fan for 5-10 minutes, depending on their size, until golden. Smaller shapes may need removing before larger ones. Allow to cool, then place on the pie before serving.