Heavenly Chocolate Cake
["1 c. butter, softened", "2 1/2 c. sugar", "2 eggs", "3 c. all-purpose flour", "2 tsp. soda", "1/4 tsp. salt", "2 Tbsp. cocoa", "2 c. buttermilk", "1 tsp. vanilla extract", "1/2 c. margarine, softened", "8 oz. cream cheese, softened", "1 lb. confectioners sugar", "2 Tbsp. cocoa", "1 c. chopped pecans"]
["Preheat oven to 350\u00b0.", "You will need 3 (9-inch) round pans."]
["butter", "sugar", "eggs", "all-purpose", "soda", "salt", "cocoa", "buttermilk", "vanilla extract", "margarine", "cream cheese", "confectioners sugar", "cocoa", "pecans"]