Plump raisins in hot water for several minutes; drain and dry on paper towels. Mix cinnamon with 2 tablespoons of the sugar and toss with raisins; set aside. Beat egg whites to soft peaks; add remaining 2 tablespoons sugar, beating until stiff peaks form. In large bowl, beat egg yolks until creamy. Stir in buttermilk and soda. Sift flour, baking powder and salt and blend into buttermilk mixture. Stir in melted butter. Fold in beaten egg whites. Gently fold in cinnamon-coated raisins. Spoon batter onto lightly greased griddle; bake, turning once. Makes 16-18 large pancakes.