MAKE THE PASTRY
Whisk together eggs and salt, stir in cold water, vinegar and vodka. Set aside.
Add the flour and salt to your mixer or food processor. Mix for a second to combine. Add the cold, cubed butter and pulse or process until the crumbs are pea size.
Add the egg mixture into the flour mixture and continue processing until the dough starts sticking to itself a bit, but is not formed yet.
Pour the content of the mixer onto a clean work surface and start gathering and sticking the dough together with your hands, trying to work it as little as possible. Form a ball and knead it for a couple of seconds until a dough forms. Don'tt work with it too much.
Shape the dough into a log and then cut it into 4 equal pieces. Roll each piece into a ball, cover with plastic wrap and refrigerate for 1-2 hours.
MAKE THE PUMPKIN CUSTARD
First cook the pumpkin. Cut it in half and scoop out all the seeds. Place it face down on a foil lined baking tray and cook in a 350 degree oven for 40 - 50 mins or until its nice and soft. Scoop out the flesh and put it in a food processor or in a blender and puree until smooth. Set aside.
In a large bowl, combine the cornstarch and the salt. Add a little bit of cream to make a paste and whisk until there are no lumps. Add the rest of the cream and whisk well making sure there are no lumps.
Add all the egg yolks and whisk well to combine. Set aside.
In a medium pot, add the pumpkin, the spices, bourbon, sugar and milk. Slice the vanilla bean in half and scrape out the sticky vanilla and add it to the pumpkin. Cook on medium heat until it is warmed through and almost boiling.
Add the pumpkin mixture slowly to the egg mixture, whisking as you add it. Pour it back into the pot and heat the whole thing to a boil whisking the whole time. Boil for 2 mins and remove it from the heat. Pour it into a container to cool and put a piece of cling wrap or parchment on the top of it so that it doesn't get a skin on the top. Let it cool to room temperature.
BAKE THE PASTRY
Preheat oven to 400F. Set the rack in the middle.
On a clean surface, roll out 1/2 of 1 dough ball, until about 12.5 inches in size. Dusting the surface with flour as needed. Then using a 10 or 11 inch plate or round pan, cut the pastry into a circle. Don't discard the scraps or roll them into a ball. You will need some of them. Place the pastry circle on a parchment lined tray.
Prick with a fork all over, to prevent uneven rising. Bake for 5-7 minutes, until lightly golden. Repeat with the rest of the dough, to make 8 layers.
Bake about half of the scraps from cutting out the circles. When they are done, crumble them all up into pieces and set aside.
Let the layers cool completely.
ASSEMBLE THE CAKE
Place a dab of custard on a serving platter. Place first pastry layer and press to adhere.
Place about 6 large spoons of custard and smooth it around. Place another pastry layer on top. Repeat with the rest of the custard and pastry. Finish with a layer of custard and then sprinkle a couple tablespoons of shredded pastry scraps on top of the cake.
Smooth a layer of custard around the edges of the cake and then pat some pastry scraps around the edges of the cake as well.
If you want to add some whipped cream, you can do that too.
Place the cake in the fridge or a cool place to chill and let the layers absorb some of the custard. Let it sit for 3 hours.
MAKE THE CARAMEL
In a small saucepan over medium heat, whisk together the butter, sugar, whipping cream and salt. Bring it to a boil (this should take about a min), then reduce the heat and simmer for 5 mins, whisking often.
Stir in the rum and remove from heat. Pour the caramel into a heat proof container and set aside.
Let the cake come to room temperature before serving.
Slice pieced of the cake using a sharp knife and top with the caramel sauce and whipped cream if you like.