Aunt Peggy's Sweet Potato Souffle

INGREDIENTS

• 1 cup packed light brown sugar
• 3 cups cooked and mashed sweet potatoes, from about 2 to 3 small baked potatoes
• 1 cup chopped pecans
• 1 cup granulated sugar
• 1 tablespoon vanilla extract
• 4 tablespoons unsalted butter, about 1/2 stick, cubed, at room temperature
• 1/2 cup milk
• 3 eggs, beaten
• 1/2 teaspoon salt
• 8 tablespoons unsalted butter, about 1 stick, melted
• 1/2 cup self-rising cake flour