1. Stir baking soda into buttermilk in medium bowl until dissolved; set aside.
2. Heat oven to 350°F. Grease and flour 13x9x2-inch baking pan.
3. Stir together flour, 1 cup sugar, cocoa and salt. Add oil, buttermilk mixture, egg yolks and vanilla; beat until smooth. Beat egg whites in small bowl until soft peaks form; gradually add remaining 1/2 cup sugar, beating until stiff peaks form. Gently fold egg whites into chocolate batter. Pour batter into prepared pan.
4. Bake 30 to 35 minutes or until cake springs back when touched lightly in center. Cool in pan. Cut into squares; top each square with scoop of ice cream and serving of FLAMING CHERRY SAUCE. 12 to 15 servings.
* To sour milk: Use 1 tablespoon white vinegar plus milk to equal 1 cup.
FLAMING CHERRY SAUCE
1 can (16 or 17 ounces) pitted dark or light sweet cherries, drained
(reserve 3/4 cup liquid)
1-1/2 tablespoons sugar
1 tablespoon cornstarch
1/2 teaspoon freshly grated orange peel
1/4 cup kirsch (cherry-flavored liqueur) or brandy
Stir together reserved cherry liquid, sugar, cornstarch and salt in chafing dish or medium saucepan. Cook over medium heat, stirring constantly, until mixture boils, about 1 minute. Add cherries and orange peel; heat thoroughly.
Gently heat liqueur in small saucepan over low heat; pour over cherry mixture. Carefully ignite with match. Stir gently; serve as directed. (Repeat procedure for sufficient amount of sauce for entire cake.) 4 to 6 servings.
QUICK AND EASY FLAMING CHERRY SAUCE: Combine 1 can (21 oz.) cherry pie filling with 1/4 cup orange juice in chafing dish or medium saucepan; heat thoroughly. Gently heat 1/4 cup kirsch (cherry-flavored liqueur) in small saucepan; pour over cherry mixture. Carefully ignite with match. Stir gently; serve as directed. (Repeat procedure for sufficient amount of sauce for entire cake.) 6 to 8 servings.