Preheat the oven to 350° Fahrenheit. Line an 8x8-inch baking pan with parchment paper and set aside.
Make the pumpkin pie spice by combining the cinnamon, ginger, nutmeg, cloves, and allspice in a small bowl. Whisk to combine. Transfer to an airtight container and set aside.**
To make the crust, combine the rolled oats, oat flour, brown sugar, cold cubed butter, pumpkin pie spice, and salt in a large bowl. Using a pastry cutter or two forks, cut in the butter until you get a crumbly mixture with small pieces of butter throughout. You don’t want to completely cream the butter into the mixture or you’ll end up with a tough, oily crust. The crust mixture should hold together when pressed.
Remove one cup of the crumble mixture and set aside. Transfer the remaining crumble mixture into the prepared baking dish and press it into an even layer. Place the crust in the preheated oven and bake for 10 minutes, until the edges are just starting to turn slightly golden.
While the crust is baking, prepare the pumpkin filling. Combine the pumpkin puree, coconut cream, almond butter, maple syrup, brown sugar, cornstarch, pumpkin pie spice, vanilla, and salt in a blender. Blend on high until everything is combined and smooth.
Pour the pumpkin filling over the par-baked crust and smooth it into an even layer. Take the reserved crumble and scatter it evenly over the top of the pumpkin mixture. Press it down lightly to make sure it’s making good contact with the pumpkin layer.
Return the crumble to the oven and bake for an additional 30 minutes, until the pumpkin is set and the crumble topping is beginning to turn golden brown.
Remove from the oven and let it cool completely before slicing and serving. Store leftovers in the fridge for 3-4 days or in the freezer for up to 3 months.