8 tbsp unsalted butter, cut into 1" chunks
5 pounds sweet potatoes, peeled and cut into 1" cubes
3/4 cup packed light brown sugar
1/2 cup water
1 1/2 tsp table salt
1/2 tsp ground black pepper
2 cups pecan halves
1/4 cup packed light brown sugar
1 egg white, lightly beaten
1/8 tsp table salt
pinch cayenne pepper
pinch ground cumin
1. For the sweet potatoes: Melt butter in a large Dutch oven over medium-high heat. Add the sweet potatoes, brown sugar, water, salt and black pepper; bring to a simmer. Reduce the heat to medium-low, cover, and cook, stirring often, until the sweet potatoes are tender (a paring knife can be slipped into and out of the center of the potatoes with very little resistance), 45 to 60 minutes.
2. When the sweet potatoes are tender, remove the lid and bring the sauce to a rapid simmer over medium-high heat. Continue to simmer until the sauce has reduced to a glaze, 7 to 10 minutes.
3. For the topping: Meanwhile, mix all the ingredients for the topping together in a medium bowl; set aside.
4. Adjust an oven rack to the middle position and heat the oven to 450ºF. Pour the potato mixture into a 13 by 9 inch baking dish (or a shallow casserole dish of similar size). Spread the topping over the potatoes with a rubber spatula. Bake until the pecans are toasted and crisp, 10 to 15 minutes - watching periodically to make sure the topping doesn't burn. Serve immediately.