Method
Preparation
Preheat your oven to 350°F (175°C).
In a large bowl, combine mashed sweet potatoes, brown sugar, milk, melted butter, vanilla extract, cinnamon, and salt until well mixed.
Pour the sweet potato mixture into a greased baking dish and spread it evenly.
Making the Streusel
In another bowl, mix together the chopped nuts, flour, sugar, and softened butter to create the streusel topping.
Use your fingers or a fork to combine until crumbly.
Baking
Sprinkle the streusel mixture evenly over the sweet potato layer.
Bake for 30–35 minutes or until the topping is golden brown and the filling is heated through.
Let it cool slightly before serving so the topping sets and the flavors meld.
Notes
Tips: Roast or boil sweet potatoes until very tender for the smoothest mash; don’t overmix the sweet potato filling. Allow the casserole to rest for 10 minutes before serving to prevent a soggy bottom.