The type of texture you want is, I believe, a cooked icing. Icing is generally thinner and contains less fat than a frosting. Here is one from the Betty Crocker cook book described as follows. "Tases like a cooked fudge frosting. Very dark and chocolately. No eggs." Melt together over hot water 3 T. shortening and 3 oz. bittersweet chocolate. Blend in 2 C. sifted confectioners sugar, 1/4 t. salt, 1/3 C. milk, 1 t. vanilla. Stir until smooth. Place bowl in ice water and continue stirring until thick enough to spread. If icing too soft and doesn't "set up", reduce the amount of shortening. Hope this is what you're looking for.