• Preheat the oven to 325°F and butter a 2-quart baking dish.
  Butter for the baking dish
• Mix the mashed sweet potatoes, 5 tablespoons of butter, and 1/4 cup of brown sugar until well blended. Whisk in the eggs, milk, vanilla, and salt.
  5 to 6 cups warm mashed sweet potatoes | 5 tbsp butter | 1/4 cup brown sugar | 2 large eggs | 1/2 cup milk | 1 1/2 tsp vanilla extract | 1/2 tsp fine salt
Use well-drained mashed sweet potatoes if they were freshly cooked, so the filling doesn’t get watery.
• Spoon the sweet potato mixture into the prepared baking dish.

Prepare the Topping

• Combine the melted butter, brown sugar, flour, and a pinch of salt in a medium bowl. Stir until the mixture forms clumps, then incorporate the pecans.
  4 tbsp melted unsalted butter | 1/2 cup brown sugar | 1/2 cup all-purpose flour | 1 pinch fine salt | 2/3 cup chopped pecans
• Sprinkle the pecan mixture over the sweet potato filling and bake the casserole for 30 to 40 minutes or until set.
Let the casserole stand for 10 minutes before serving so it sets a bit.