Wash and scrub sweet potatoes. Using a fork, pierce sweet potatoes through out and place on a bake sheet lined with foil and then covered loosely with a second sheet of foil. Bake at 400 degrees Fahrenheit for about 45-60 minutes or until sweet potatoes are fork tender.
Scrap out sweet potato flesh and measure out five cups. Allow to cool for five to seven minutes. Add to a food processor with the sugar, spices, salt, eggs, vanilla, buttermilk and butter. Pour mixture into a 13×9 glass baking dish and bake for about 20-25 minutes or until the exterior slightly browns. The dish can be prepared a day in advance and refrigerated.
In a bowl, mix together the oats, pecans, almond flour, sugar, flax, cinnamon, salt and butter.
Reduce heat to 350 degrees Fahrenheit. Top the sweet potatoes with an even layer of the oat and nut topping and spritz with a little olive oil in an oil atomizer (or nonstick cooking spray). Bake for 20 minutes, or until the topping crisps up and turns golden brown.