Place the flour and salt in a food processor and pulse to combine. With the machine running, begin to add the butter, one piece at a time. Continue to pulse until the mixture looks like coarse meal. Add the vinegar. With the machine still running, begin to slowly add the ice water, 1 tablespoon at a time, waiting a moment or two before each addition, until the dough begins to form into a ball in the bowl of the processor.
Remove the dough and place on an oil-sprayed surface and roll out into a circle that is one inch larger around than the pie pan and place the dough in it, leaving a 1-inch edge around the perimeter of the pan. Create a nice border around the pie pan, trimming off any excess dough. Place the pie crust in the refrigerator while you make the pumpkin filling.
Preheat the oven to 350 degrees.
Wash and cut the kabocha squash in half and remove the seeds. Place cutside down in baking dish with about 1/2 inch of apple juice, cover with parchment paper and foil, and bake for about 45 minutes or until an inserted knife comes out easily. Leave the oven on. When the squash is cool enough to handle, scoop out the pulp with a large spoon. Reserve the pulp in a bowl and discard the skin.
In a blender or food processor, combine 3 cups of pulp, milk, sugar, maple syrup, eggs, cinnamon, ginger, cloves, and salt. Mix well. Remove the pie crust from the refrigerator; pour the batter up to the rim of the dough. Bake for approximately 45 minutes. If the pie begins to brown too much, place some foil over it. Bake until an inserted toothpick comes out clean. The pie should be golden brown.