Make your crust by processing all the ingredients together in a food processor.
Form the walnut date mixture into an about 9inch pie pan. Use your fingers to press the dough down into the pans to tightly fit. Place in the fridge to chill while you make the top layer filling.
To make the filling, pour all the ingredients into a blender. Turn it on until a smooth mixture forms, a couple of minutes.
Do a quick taste test of the filling. Adjust the spices as desired.
Remove the chilled pan from the fridge. Spoon the pumpkin filling over the bottom base layer and smooth to even out. Garnish the tops with a single walnut for each slice. Place in the freezer until set, about 30 minutes. Keep in the fridge or freezer.