Preheat oven to 350F. Butter a 9 inch springform pan
In a large capacity food processor add the pecans, melted butter, erythritol, and cinnamon. Process until finely chopped and combined.
Spread the pecan mixture into the bottom the the buttered pan and gently press with your fingers working it a little up the sides of pan.
Bake crust for 8 minutes, remove from oven and let cool while you make the filling
Wipe the food processor bowl with a paper towel. Inside place the cream cheese, eggs and yolks and process until well combined scraping bowl sides with a spatula if needed, pumpkin puree, erythritol, vanilla extract and the pumpkin spice mix. Process until very smooth, use a spatula to scrape bowl walls once in a while. I like to taste my filling and adjust the flavorings/sweetness.
Pour the filling over the crust and bake for 55 mins. In the meantime make the sour cream topping by whisking the sour cream, erythritol, orange zest, and extracts together until smooth.
When the 55 mins have passed, pour and gently spread the sour cream topping on top of the cheesecake and bake for and additional 7 mins.
Turn oven off and open door slightly leaving the cheesecake inside the oven to cool(it may take a couple of hours). When cool remove from oven and chill in fridge for up to 24 hrs before serving( I never have the patience to wait that long before I eat it)