1. First make the biscuit base. Put the butter in the small saucepan and cook for a few minutes until it is melted and bubbling. While the butter is melting, put the biscuits into the sandwich bag and secure tightly before using the rolling pin to bash them into a rubble with no big chunks of biscuit left. When the butter has melted, add the biscuit rubble to the butter and stir with a wooden spoon. When thoroughly mixed, put the mixture into the ceramic flan dish and press down with the back of a wooden spoon or a spatula to make a flat surface. Put the base into the fridge to cool for 30 minutes while you make the filling.
2. Next prepare the pumpkin. Peel the outside of the pumpkin with a peeler or sharp knife. Then cut off the top and bottom and cut in half down the middle and then in quarters. Use the knife and then the dessert spoon to scoop out the membrane and seeds. When all four quarters are deseeded, cut each quarter into large roughly inch-sized chunks.
3. Melt the butter for the filling into the large saucepan before adding the pumpkin chunks and stirring with the wooden spoon. When each piece is covered in butter, cover with a lid and leave to cook for 20 to 30 minutes. Check the pan from time to time to check that the pumpkin isn't burning on the sides of the pan.
4. While the pumpkin is cooking, preheat the oven to 180'C. To test whether the pumpkin is cooked, use a sharp knife to see whether it is soft. When it is, take off the heat and use a hand-blender to whiz it to a fine puree.
5. When it is whizzed, add the sugar, spices and cream to the pumpkin and give it a good stir before giving it a taste to make sure the balance of all the ingredients is right. Finally add in the sultanas and give it a last taste before adding the eggs to the mixture and giving it a final stir.
6. Pour the pumpkin mix into the prepared flan dish and even out with the wooden spoon to make sure it is level. Put the flan dish on a baking tray to make it easier to carry and put in the oven for 30 to 40 minutes until the filling is set, is a lovely golden brown and is starting to brown around the edges. Pumpkin sizes vary so you may have a little extra filling left. If you do, you can put in a smaller dish and cook for a smaller length of time and have extra pumpkin pie!
7. When the pie is cooked, take out of the oven and leave to cool for 5 minutes before serving a large slice with cream or just enjoy on its own for a perfect autumnal pudding!