Preheat oven to 350 degrees F. Butter or oil a 9 x 13 casserole dish.
Peel and chop the sweet potatoes into medium-sized chunks. In a large pot of water, boil the sweet potatoes until tender, about 10 minutes.
Drain the sweet potatoes and transfer to a large mixing bowl. Mash the sweet potatoes along with the beaten eggs, 1/2 cup maple syrup, 2 tablespoons melted butter, coconut milk, nutmeg, and a pinch of salt and pepper. Spoon the mashed sweet potato mixture into the baking dish.
In a small bowl, mix the chopped pecans, 2 additional tablespoons melted butter, and 1 tablespoon maple syrup. Sprinkle mixture evenly over the top of the sweet potatoes. Bake for about 40 minutes.