Preheat and prep. Heat the oven to 350°F (175°C).
Place pecan halves on a baking sheet and toast for 6–8 minutes until fragrant. Set aside to cool.
Make the crust. In a bowl, whisk almond flour, coconut flour, sweetener, and salt. Add melted butter, egg, and vanilla.
Stir until a soft dough forms.
Press and par-bake. Press dough evenly into a 9-inch pie pan, going up the sides. Prick the base with a fork. Bake 10–12 minutes until lightly set and just starting to color.
Let cool slightly.
Start the filling base. In a small saucepan over medium-low heat, melt butter. Add sweetener and stir until dissolved and glossy, 2–3 minutes. Remove from heat and cool 5 minutes so it doesn’t scramble the eggs.
Whisk the custard. In a bowl, whisk eggs, heavy cream, vanilla, maple extract, molasses (if using), and salt.
Sprinkle xanthan gum over the mixture and whisk vigorously to avoid clumps.
Combine. Slowly pour the warm butter-sweetener mixture into the egg mixture while whisking. The filling should become smooth and slightly thick.
Assemble. Scatter toasted pecans evenly over the par-baked crust. Pour the filling over the nuts, nudging to distribute evenly.
Pecans will float slightly—that’s fine.
Bake. Bake 30–40 minutes until the edges are set and the center jiggles slightly like gel. If the crust browns too fast, tent the edges with foil for the last 10–15 minutes.
Cool and set. Let the pie cool at room temperature for at least 2 hours, then chill 1–2 hours for the cleanest slices. Slice with a sharp knife, wiping between cuts.
Serve. Enjoy as-is or with a dollop of unsweetened whipped cream.
A pinch of flaky sea salt on top makes the flavors pop.