Set oven to 400F.
Wash and peel the sweet potatoes, then chop them into large chunks.
Bring a pot of water to a boil and add the potato chunks. Cook until tender, about 15 to 20 minutes. Drain the sweet potato, then place the pieces in a bowl.
Quickly mash the potatoes with a fork – this will make them easier to whip using a (hand) mixer. Add the vegan butter, then mix them using a hand mixer for about 1 minute. Then add the remaining ingredients for the filling and mix until smooth and whipped.
Add the whipped potatoes to a baking dish and evenly spread them out using a spatula. Bake in the oven for 15 to 17 minutes, or until the top is golden brown.
While the filling bakes, add the ingredients for the topping to a food processor and pulse blend. Do not pulverize – you should still have chunks of pecan.
Evenly add the topping to the top of the sweet potato filling using a spatula. If desired, sprinkle a little coconut sugar on top.
Bake for 25 to 30 minutes, or until the crust is golden brown and crispy to touch. Allow the sweet potato to cool for about 5 to 10 minutes – to allow the crust to further harden – before enjoying.