Move oven rack to lower third of the oven. Preheat oven to 350°F. Lightly grease a deep 9" pie plate and set aside.
Place almond flour, arrowroot starch, maple or coconut sugar, and sea salt into a food processor fitted with the chopping blade. Pulse until combined.
Drop the coconut oil (it should be mostly solid) by the tablespoon over the dry ingredients. Pulse a few times until combined. It will look kind of like wet sand.
While pulsing, pour the egg through the feed hole. Pulse a few more times until everything is well-combined. It won't form a ball, but it will stick together when lightly pressed.
Transfer the mixture to the pie plate. With your hand, evenly distribute over the bottom and up the sides, pressing so the crust holds together. If desired, flute the edge.
Bake the crust for 10-12 minutes or until it looks "dry" and is barely golden on the edges. Remove and let cool for 10 minutes.
Reduce oven temperature to 300°F.
Meanwhile, wipe out the food processor bowl and fit with the chopping blade. Place all of the filling ingredients into the food processor and blend until well-combined. Stop and scrape down sides to make sure all of the pumpkin is evenly incorporated and no lumps remain. Remove bowl from food processor and gently rap on the counter to release any air bubbles from the filling.
Pour the filling into the partially baked and cooled crust. (It will still be warm, but shouldn't be piping hot.) Smooth the top of the filling and gently draw a fingertip through the filling in a circular pattern.
Place pie into the 300°F oven and bake for 60-75 minutes. Start checking at the 60 minute mark and check every 5-7 minutes. If using a glass pie plate, bake until the center just wobbles a little. If using a ceramic or stoneware pie plate, remove when the center is a little jiggly in the center, but the 2-3" around the perimeter are set. The filling will continue to cook after the pie comes out of the oven. Allow to cool completely to room temperature, then refrigerate until cold.
Cut into wedges and serve topped with whipped coconut cream, if desired.