Perfect Chocolate Cake
["1 c. cocoa", "2 c. boiling water", "2 3/4 c. sifted all-purpose flour", "2 tsp. baking soda", "1/2 tsp. salt", "1/2 tsp. baking powder", "1 c. butter, softened", "2 1/2 c. sugar", "4 eggs", "1 1/2 tsp. vanilla"]
["In medium bowl, combine cocoa with boiling water, mixing with wire whisk until smooth.", "Cool completely."]
["cocoa", "boiling water", "flour", "baking soda", "salt", "baking powder", "butter", "sugar", "eggs", "vanilla"]