Preheat your oven to 350°F (175°C). In a mixing bowl, combine the almond flour, melted butter, egg, sweetener, ground cinnamon, and vanilla extract. Stir until a soft dough forms.
Line a 9x13 inch baking pan with parchment paper. Press the dough evenly into the bottom of the pan to create a crust. Bake for 10 minutes, then set aside to cool slightly.
In a separate bowl, use a hand mixer to whip the softened cream cheese and sour cream until it's super smooth. Beat in the egg, sweetener, and vanilla extract until everything is well combined and creamy.
In another mixing bowl, combine the softened cream cheese and pumpkin puree. Whip them together with a hand mixer until smooth. Mix in the egg, sweetener, and vanilla extract until evenly blended.
Pour the plain cheesecake batter evenly over the cooled crust in the baking pan. Then, gently spoon the pumpkin layer on top of the cheesecake layer and smooth it out.
Bake for 30-35 minutes, or until the center of the bars has just a slight wobble. Let them cool at room temperature for 30 minutes, then transfer them to the fridge to chill for at least 4 hours, or ideally overnight, until fully set.
Once completely firm, cut the bars into squares. For an extra touch of deliciousness, top with optional homemade whipped cream and enjoy your wholesome, low-carb treat!