For the pecan crust, grease a springform pan that's 8 inches in diameter and at least 2-1/2 inches deep with coconut oil. Line the bottom with parchment paper, and cut a 2-1/2 inch wide strip of parchment paper to line the sides of the springform pan with, as well. Set it aside.

In the bowl of a stand mixer fitted with the paddle attachment, mix together the coconut oil and sugar at medium low speed until smooth. Add the pecans, cinnamon, and salt and reduce speed to low, mixing until just combined. Evenly distribute the mixture across the bottom of the springform pan, patting it into place to create a firm and even layer with your fingertips.

Preheat the oven to 400 degrees Fahrenheit. Place the sweet potatoes on a baking sheet and pierce them all over with a fork. Place them in the oven and roast until tender when poked with a fork, about 50 to 60 minutes. Remove from the oven and allow to cool enough you're able to handle them comfortably, then remove the skin and discard it. Chop the sweet potato into roughly 1-inch cubes and set aside.

Decrease oven temperature to 350 degrees Fahrenheit. Move one of the racks to the lowest rack possible, and fill a medium-sized pot 3-inches deep with water and place it on the bottom rack. This will create a steam bath in the oven and help the cheesecake cook evenly and help prevent cracking.

Place the cheesecake in the fridge for 4 hours or overnight. Run a small butter knife between the parchment paper and the sides of the springform pan to loosen any hardened coconut oil. Release the sides of the springform pan and remove it, then peel away the parchment paper from the sides of the cheesecake. Sprinkle the crushed pistachios around the edges of the cheesecake. Slice and serve immediately.