Instructions

1. Preheat the oven to 425 degrees Fahrenheit. Line a large, rimmed baking sheet with parchment paper to catch the sweet potato drippings. Grease a 9-inch square baker (or any other 2-quart baker) with butter or cooking spray. Remember to leave the butter at room temperature so it has time to soften.
2. To prepare the filling: Prick each sweet potato with a fork about 5 times so steam can escape. Place the whole sweet potatoes on the prepared baking sheet and bake until they yield easily to a gentle squeeze (use oven mitts!), somewhere between 45 minutes to 1 hour 15 minutes, depending on their size. Set them aside to cool for a few minutes.
3. Reduce the oven temperature to 350 degrees. Once the potatoes are cool enough to safely handle, slice each one in half. Use a big spoon to scoop the insides into a large mixing bowl, then discard the skins.
4. Add the melted butter, milk, maple syrup, vanilla, nutmeg and salt to the bowl. Use a hand mixer to whip the ingredients together until they’re smooth and creamy (alternately, use a potato masher or stir by hand). Scoop the mixture into the prepared baker and spread it in an even layer.
5. To prepare the topping: In a medium bowl, combine the softened butter (if it’s not soft enough to stir yet, microwave it in 6 to 8 second intervals), sugar, pecans, optional rosemary, cinnamon and salt. Stir until the mixture is evenly incorporated. Dollop small forkfuls evenly all over the sweet potato filling.
6. Bake for 30 minutes, until the pecans are golden and fragrant, and the filling is sizzling around the edges and warmed all the way through. Serve. Leftovers will keep well in the refrigerator, covered, for 4 to 5 days.