Preheat your oven to 400 degrees. Pierce the sweet potatoes with a fork and place them on a rimmed baking sheet. Bake them in the oven until they are very soft, 60-90 minutes, depending on their size. Turn the potatoes over once during the baking time.
When the sweet potatoes are finished cooking, allow them to cool. Once they are cool, use a knife to cut open the skin and peel it out. Discard. Put the sweet potato flesh into a large bowl and mash well. Add the next 8 ingredients (through orange zest, if using) and mix well. Place the sweet potato mixture in a 2-quart baking dish.
In a small bowl, mix together the pecans, coconut oil, maple syrup, and cinnamon. Place the pecans on top of the casserole as shown in the pictures.
Reduce the oven temperature to 350 degrees and bake for 20-25 minutes, until the top is lightly browned. Enjoy!