Preheat the oven to 350º F. Grease a 9 in (23 cm) springform pan or line the bottom with parchment paper. To make the crust, stir the almond flour, melted butter, erythritol, and vanilla extract in a medium bowl until well combined. Press the dough into the bottom of the prepared pan. Bake for about 8-10 minutes, until barely golden, then let cool at least 10 minutes.
Mix together the cream cheese, 2/3 cup erythritol, and vanilla in a medium bowl just until smooth.
Mix in eggs one at a time, mixing well after adding each one. Set aside 1 cup of the mixture.
Mix 1/3 cup erythritol, pumpkin, cinnamon, and pumpkin pie spice into the remaining mixture.
Spread the pumpkin batter into the crust.
Dollop the cream cheese batter by spoonfuls onto the top.
Swirl with a knife to create a marbled effect. Bake 45 minutes or until filling is set and center is just barely jiggly. Turn off oven but keep oven door propped open for 10 minutes. Remove and allow to cool to room temperature. Run a knife around the edge of the pan before removing pan rim. Chill for at least 4 hours before serving.