Make the crust for the pie by combining the dry ingredients into your foodprocessor and quickly pulsing until combined. Cut the butter into cubes (making sure the butter is icecold!) and pulse them through the dry ingredients
Once combined add about 3 tbsp of the water into the mix and pulse again until it resembles fine crumbles. When you pinch it it should stay together. Turn out onto a kitchencounter and quickly make a ball of dough and put it in the fridge for 30 mins to an hour (or longer, you can do this the day before if you want)
Rol out the dough and line your cake tin. Blind bake the pastry for 20 minutes with foil and baking weights. Remove the foil, brush with eggwash and bake again for 10 minutes until golden. Leave to cool.
Preheat the oven to 200 C. Cut the pumpkin into chunks (you can leave the skin on or if you prefer you can take it off too) put on a baking tray and roast in the oven until done.
Depending on the size of your chunks it will take longer or shorter. Mine took more then an hour as the squash was huge and I didn't cut them very small.
Once cooked, take out, leave to cool and then scoop out the flesh with a spoon and blend until you have a smooth puree.
Mix the puree with the double cream, the eggs and the sugar and whisk to combine.
Pour into the cooled tart tin and put in the preheated oven for about 45 minutes or until done!