Preheat the oven to 375o degrees C. Grease an 8-inch pie plate with butter.
Place the flour, almond flour, and salt in a large bowl.
Add butter and use your fingers or a pastry cutter to work the butter into the flour until the mixture resembles small peas.
Pour in the buttermilk and mix with a spatula, drizzling in more buttermilk as needed (no more than 1 tablespoon at a time), until the dough just comes together (a few dry spots are ok). Turn the dough out onto a floured surface and gently knead until no dry spots remain about 1 minute.
Divide the dough in half. Shape each piece into a circular disk. Wrap the dough in plastic wrap. At this point, you can place the dough in the fridge for up to one week or use as directed in your recipe.
Fit the pie crust into the prepared pie plate. Line the crust with parchment paper and fill with pie weights, beans or rice. Transfer to the oven and bake until the crust is set, 30 to 35 minutes.
Remove pie weights and continue to bake until the crust is golden about 10 minutes. Remove from the oven. Reduce the oven temperature to 160o.
To make the pumpkin filling, mix together the pumpkin, heavy cream, eggs, maple syrup, brown sugar, vanilla, cinnamon, ginger, nutmeg, cardamom, cloves, salt, and pepper in a mixing bowl until combined. Pour the mixture into the baked crust.
Transfer the pie to the oven and bake for 50-55 minutes or until the center no longer jiggles.
Remove from the oven and let cool, and then place in the fridge to cool completely.
When ready to serve, you can top the tart with whipped cream, if desired. Slice and serve!