2 tbsp. butter
1 pkg. Betty Crocker creamy frosting mix
1/4 c. milk (plus 2 tsp. with chocolate fudge mix)

Heat butter in milk over low heat until butter melts and mixture just begins to simmer. Remove from heat; stir in frosting mix (dry). Heat over low heat, stirring constantly with rubber scraper, until smooth and glossy, 1 to 2 minutes. Do not over cook. Pour into 9 x 5 x 3 inch loaf pan. Chill until firm. Cut into squares.