Drain 2 cans (29 oz each) and 1 can (15 oz) sweet potatoes or yams. Mash in large bowl. Add 1/2 cup melted butter, 2 teaspoons pumpkin pie spice, 2 teaspoons salt and 1/2 cup packed brown sugar. Mix, and add 1 cup buttermilk, stirring with spatula until well combined. Add 3 eggs, beaten; mix well.