2 tbsp. flour
1/2 c. milk
1/4 c. butter
1/4 c. shortening
1/2 c. sugar
1 tsp. vanilla

Mix until smooth flour and milk. Cook over low heat until thick paste forms. When thick pour into saucer to cool. Cream butter, shortening and sugar. Whip until looks like whipped butter. Gradually add flour paste mixture. Continue beating 5 minutes. Add 1 teaspoon vanilla, beat 1 minute more. Will frost two 8 inch cakes.