Preheat and prep. Heat your oven to 350°F (175°C). Lightly grease a 9-inch pie dish or line with parchment for easy slicing.
Make the crust. In a bowl, whisk almond flour, sweetener, and salt.
Stir in melted butter, egg, and vanilla until a soft dough forms.
Press and par-bake. Press the dough evenly into the pie dish, pushing it up the sides. Prick the base with a fork. Bake for 10–12 minutes until lightly set but not browned.
Let cool for 5 minutes.
Mix the filling. In a large bowl, whisk pumpkin puree, sweetener, eggs, heavy cream, spices, salt, and vanilla until smooth. Don’t overbeat; you want minimal air bubbles.
Fill the crust. Pour the filling into the warm crust. Tap the dish gently on the counter to release any small bubbles.
Bake. Bake for 40–50 minutes, until the edges are set and the center still has a slight wobble.
If the crust browns too quickly, tent the edges with foil.
Cool completely. Place on a wire rack and cool to room temperature, about 2–3 hours. The filling will finish setting as it cools.
Chill. For the best texture and clean slices, refrigerate for at least 4 hours or overnight.
Serve. Slice with a sharp knife, wiping the blade between cuts. Add whipped cream and a sprinkle of cinnamon if you like.