For the crust, work the chilled butter into the flour and sugar. Add the buttermilk and toss together until a shaggy dough appears. Turn out onto a clean work surface and together into a disk. Wrap the disk and let it rest in the fridge for one hour.

            Roll out the dough into a long triangle and fold one short end to the middle and the other short end to the middle. Then fold into a book. Turn the dough and roll out again into a long rectangle. Fold the short end to the middle and the other short end to the middle and fold like a book. Wrap and chill again for another 30 minutes.

            Preheat the oven to 400 degrees.

            Roll out the dough into a 10-inch circle. Form in an 8-inch pie plate and crimp the edges. Line the crust with parchment paper and fill with pie weights or dried beans. Bake in the preheated oven for 15 minutes then remove the pie weights and reduce the oven temperature to 375 degrees. Continue to bake until golden brown, about 25-30 minutes.

            To prepare mousse, in a small bowl, add gelatin and water; stir to combine and set aside to allow gelatin to bloom.
            In a medium saucepan set over medium heat, add yolks, ½ cup cream, sugar, pumpkin puree, vanilla, spices, and salt. Cook, stirring constantly with a silicone spatula, until mixture thickens, about 5 minutes. Whisk gelatin and water into pumpkin mixture and refrigerate for about 15 minutes.
            Once the mixture has come to room temperature, whisk the egg whites to medium peeks and fold into the pumpkin mixture.

Dump into the pie shell and let chill in the fridge, uncovered at least 4 hours but is best overnight.

Whip the whipping cream and maple syrup together right before serving.

*If making the puff pastry pumpkins, cut the prepared puff pastry into small pumpkins and place on a baking sheet. Top the entire baking sheet with another baking sheet and bake in a 400-degree oven for 10 minutes.