Preheat your oven to 400°F (200°C). Peel and cube the sweet potatoes, then toss them in a large bowl with extra virgin olive oil, ground cinnamon, and nutmeg. Spread the seasoned sweet potatoes on a baking sheet and roast for about 50-60 minutes, until they are tender and slightly charred. Allow them to cool slightly before moving on.

Reduce the oven temperature to 375°F (190°C) and grease a 9x13 inch baking dish with butter or non-stick spray. In a large mixing bowl, combine the roasted sweet potatoes with almond milk, vanilla extract, organic brown sugar, pure maple syrup, and all the spices. Stir until well combined, keeping some chunks of sweet potato for texture. Then, pour the mixture into the prepared baking dish, tucking in bits of unsalted butter throughout the filling.

In a small bowl, combine the raw pecans with a drizzle of maple syrup, stirring to coat. Spread this mixture evenly over the casserole filling, ensuring an even layer for that delightful crunch.

Cover the casserole with aluminum foil and bake for 15 minutes to allow the flavors to meld. Afterward, remove the foil and bake for an additional 15 minutes, until the topping is golden brown and the marshmallows have melted. Let the casserole cool for a few minutes before serving.