• Preheat the oven to 350ºF (177ºC).
• Spray a casserole dish² with nonstick spray. Set aside.

PECAN TOPPING

• In a medium size bowl, combine the brown sugar, flour, melted butter, and salt. Toss with a fork to combine.
  ½ cup (100g) firmly packed light brown sugar, ¼ cup (30g) all-purpose flour, ¼ cup (57g) unsalted butter, ¼ teaspoon salt
• Add the chopped pecans, then stir again until everything is thoroughly combined. Set aside.
  ¾ cup (90g) pecans

SWEET POTATO FILLING

• Peel the sweet potatoes, then cut into 1-2" chunks.
  4 medium sweet potatoes
• Bring a large pot of water to boiling, add the cut sweet potatoes, then boil for 15-20 minutes, or until sweet potato chunks are fork-tender. Drain and allow to cool for 15 minutes.
• When the sweet potatoes have cooled a bit, you are going to mash them. You can use the large pot you boiled them in or transfer them to a large bowl. Mash cooked sweet potatoes with a handheld electric mixer, a potato masher, or, if they're soft enough, with a large fork. I like to keep some larger chunks of sweet potatoes in my casserole, but mash to your desired consistency.
• Once your sweet potatoes¹ are mashed, add the granulated sugar, melted butter, eggs, vanilla extract, and salt. Stir to combine.
  ⅓ cup (67g) granulated sugar, ⅓ cup (75g) unsalted butter, 2 large eggs, 2 teaspoons vanilla extract, 1 teaspoon salt
• Pour the sweet potato mixture into the prepared baking dish. Sprinkle the pecan topping evenly over the top of the sweet potatoes, then bake the casserole for 30-35 minutes. Allow to cool slightly before serving. Store leftovers covered tightly in the refrigerator up to 4 days. Pecans will lose their crunch, but still be totally fine to eat. Baked casserole freezes well, up to 3 months. Thaw in the refrigerator then bake in a 200ºF (93ºC) oven until warmed through.
• Make ahead: prepare casserole through adding the pecan topping, then freeze for up to 3 months. Thaw in the refrigerator, then proceed with baking instructions. I highly recommend leaving off the pecan topping before freezing and adding it just before baking it to preserve the crunch of the pecans. You can also prepare this casserole up to 2 days in advance and store in the refrigerator until ready to bake. Again, I encourage you to leave off the pecan topping until just before baking, but you can add it whenever makes sense for your preparation, if needed.