Remove the cream cheese, sour cream, and eggs from the refrigerator and bring them to room temperature.
Preheat the oven to 350°F.
Grease the bottom and sides of a 9-inch springform pan.
Line the bottom with parchment paper.
Wrap the outside of the pan with two or three layers of heavy-duty aluminum foil.
In a bowl, combine the almond flour, chopped pecans, powdered sweetener, cinnamon, and salt.
Add the melted butter and vanilla.
Stir until the mixture resembles damp crumbs.
Press the crust firmly into the bottom of the pan.
Bake for 10 to 12 minutes, until lightly golden.
Remove the crust from the oven and reduce the temperature to 325°F.
Beat the softened cream cheese on low speed until smooth.
Add the powdered sweetener and coconut flour.
Mix on low speed until combined.
Add the sour cream, sugar-free maple syrup, maple extract, vanilla, cinnamon, and salt.
Mix just until evenly incorporated.
Add the eggs one at a time, mixing briefly after each addition.
Pour the filling over the cooled crust.
Smooth the top and tap the pan gently to release large air bubbles.
Place the springform pan inside a roasting pan.
Add enough hot water to the roasting pan to reach approximately one inch up the sides of the springform pan.
Bake for 70 to 85 minutes.
The cheesecake is done when the edges are set and the center still has a gentle wobble.
Turn off the oven and crack the door open.
Leave the cheesecake inside for 60 minutes.
Remove it from the water bath and carefully remove the foil.
Run a thin knife around the edge of the cheesecake.
Cool at room temperature for approximately one hour.
Cover and refrigerate for at least six hours or overnight.
To make the topping, melt the butter in a saucepan over medium-low heat.
Add the brown sugar-style sweetener and sugar-free maple syrup.
Whisk until the mixture begins to look smooth.
Add the heavy cream, maple extract, vanilla, cinnamon, and salt.
Simmer gently for three to five minutes, stirring frequently.
Add the pecans and cook for another two to three minutes.
Remove the topping from the heat and allow it to cool.
Spoon the warm or room-temperature topping over the chilled cheesecake.
Slice with a warm, clean knife and serve.