This recipe has been made at Iowa State University, in Ames, for so long that even 30-year employees don't know how the recipe came to be. These brownies feature buttermilk in both the batter and the icing, which creates their irresistible gooeyness.
Yield: 2 lb. + 3 ½ oz.
6 oz. all-purpose flour
.18 tsp. salt
¾ tsp. baking soda
12.06 oz. granulated sugar
6 oz. water
2 ¾ oz. canola oil
3 oz. margarine
2 ⅓ tbsp. + ½ tsp. sifted cocoa
2 ½ oz. frozen whole eggs
3 ¼ oz. buttermilk
¾ tsp. vanilla extract
Yield: 10 ounce
1 ½ oz. melted margarine
1 ⅔ tbsp. + ½ tsp. cocoa
1 ½ oz. buttermilk
6 ½ oz. powdered sugar
¼ tsp. vanilla extract
1. Sift flour, salt and baking soda together. Add sugar to sifted dry ingredients in mixing bowl. Combine water, oil, margarine and cocoa in steam kettle; heat to boiling.
2. Add boiling water to flour mixture ⅓ oz. at a time. Mix well after each addition. Batter should have smooth consistency. Add eggs, buttermilk and vanilla to mixture; mix well.
3. Portion 2 lb. + 3 ½ oz. batter into greased sheet pans. Bake at 325°F in rack oven for 25 minutes until toothpick comes out clean when inserted in center.
4. For frosting: Melt margarine in steam kettle. Add cocoa and buttermilk to margarine in kettle; bring to a boil. Remove mixture from kettle.
5. Add ⅓ of cocoa/buttermilk mixture to mixing bowl; add powdered sugar and vanilla to mixture in mixing bowl. Using flat paddle, beat mixture until creamy and all lumps have disappeared. Add remaining ⅔ of cocoa/buttermilk mixture to frosting; mix well. Caution: Overmixing will cool frosting and it will not spread easily. Frosting should be glossy forming glaze.
6. Portion 10 oz. frosting onto cooled cakes; spread. Cut cakes and serve.
Recipe by Iowa State University