Preheat the oven to 425F. Wash, dry, and prick the sweet potatoes with a fork. Wrap individually in tin foil. Bake for 1 hour. After baking, allow to cool about 20 minutes before unwrapping and handling.
Combine the remaining butter, sugar, maple syrup, pecans, and spices in a 12-inch skillet over medium heat on the stovetop. Use a rubber spatula to toss and coat for about 5 minutes until pecans are glossy and semi-thick. Remove to a piece of parchment paper or to a bowl to cool.