01 -
Preheat oven to 350°F. Poke sweet potatoes several times with a fork and arrange on a parchment or foil-lined baking sheet. Bake until a knife pierces easily, 60 to 75 minutes, turning after an hour and baking up to 15 minutes more as needed.
02 -
Remove from oven and allow sweet potatoes to cool for 20 minutes. Keep oven on for later steps.
03 -
Grease an 8x11-inch or 9x13-inch ovenproof casserole with 1 tablespoon butter. Set aside.
04 -
Peel sweet potatoes and transfer flesh to a mixing bowl. Add the remaining 1/2 cup butter, eggs, granulated sugar, vanilla extract, milk, and kosher salt. Beat with a stand mixer or hand mixer until thoroughly combined.
05 -
Spread the sweet potato mixture evenly into the prepared casserole dish.
06 -
In a separate bowl, combine chopped pecans, brown sugar, flour, and 1/4 cup softened butter. Mix with a fork or fingertips until crumbly.
07 -
Sprinkle streusel mixture evenly over the sweet potato base.
08 -
Bake at 350°F for 40 minutes or until topping is golden brown and mixture is bubbling around the edges.
09 -
Allow to cool slightly before serving warm.