01 -
Preheat oven to 350°F (175°C) and lightly grease a 9x13 inch baking dish.
02 -
Place cubed sweet potatoes in a large pot and add enough cold water to cover by 1 inch. Bring to a boil over high heat, reduce to a simmer, and cook for about 15 minutes or until fork-tender. Drain thoroughly.
03 -
Transfer drained sweet potatoes to a large bowl. Add 1/2 cup brown sugar, 1/3 cup melted butter, vanilla extract, and kosher salt. Mash until smooth and well combined.
04 -
Spread the mashed sweet potato mixture evenly into the prepared baking dish.
05 -
In a medium bowl, mix 1/4 cup melted butter with 1/3 cup brown sugar and all-purpose flour until combined. Stir in chopped pecans until evenly coated.
06 -
Sprinkle the pecan mixture evenly over the sweet potatoes. Bake for 30 to 45 minutes or until topping is golden and casserole is set.