Preheat the oven to 375°F and lightly grease a 2-quart baking dish.Add the diced butternut squash and sweet potato to a large pot and fill with water, covering by about 2 inches. Place the pot on the stove over high heat and bring to a boil. Allow to cook for about 25 to 30 minutes, until they are tender enough to mash.Meanwhile, prepare the crumble topping by combining 2 tablespoons coconut oil, 2 tablespoons vegan butter, 3 tablespoons pure maple syrup, 1 teaspoon vanilla extract, 1/2 teaspoon salt, 1 teaspoon cinnamon and 1/2 teaspoon ginger in a large bowl. Stir together then add 1 cup chopped pecans, 1 cup rolled oats, 1 cup almond flour and 1/4 cup oat flour. Continue to stir until everything is well combined and a crumble texture starts to form.Drain the squash and the potatoes in a strainer and then return them to the pot. Using a potato masher, mash them both together until smooth. Add the teaspoon of vanilla extract, 2 tablespoons butter, 3 tablespoons almond milk, 1 teaspoon salt, 1 teaspoon cinnamon and 1/2 teaspoon ginger. Stir together by hand or (recommended method) use a mixer to whip everything together for about 15 seconds.Transfer the potato mixture to the baking dish and use a spoon to smooth it down so that there surface is flat and even. Use your fingers to sprinkle the pecan crumble on top so that it covers the surface. At this point you can cover and refrigerate until ready to cook, if needed. Just be sure to leave the casserole out at room temperature for a few hours before cooking the day of.Bake in the oven for 30 minutes, or until light golden brown on top. Allow to cool for 5 to 10 minutes then serve and enjoy!