Wash and scrub sweet potatoes. Using a fork, pierce sweet potatoes throughout and place on a bake sheet lined with foil and then covered loosely with a second sheet of foil. Bake at 400 for about 45-60 minutes or until sweet potatoes are fork tender.
Scrape out sweet potato flesh and measure out 5 cups. Allow to cool for 5-7 minutes. Add to a food processor with the sugars, spices, salt, eggs, vanilla, buttermilk and butter. Pour mixture into a 13×9 glass baking dish and bake for about 25-30 minutes or until the exterior turns slightly browns. The dish can be prepared a day in advance and refrigerated.
Apples
Melt the butter in a medium saucepan over medium heat and add in the brown sugar and apples. Sautee until slightly softened and coated in the caramel, about 3 minutes. Transfer to the bowl or container. This can be made a day in advance and refrigerated
Pecan and Gingersnap Praline Streusel
Place all ingredients in a food processor and pulse 3-4 times in three seconds bursts. This can be prepared a day in advance and refrigerated
Assembly
When ready to eat, preheat oven to 350 F. Top the sweet potatoes with an even layer of the caramelized apples and then the praline topping. Bake for 20 minutes, or until the praline topping crisps up and turns golden brown.