Cooked Icing
["1 c. milk", "4 Tbsp. flour", "1 stick butter", "1/2 c. shortening", "1 c. sugar", "1 tsp. vanilla"]
["Cook milk and flour until thick.", "Cool.", "Beat butter, shortening, sugar and vanilla until sugar is dissolved.", "Add milk mixture to sugar mixture until fluffy.", "Add peanut butter to taste.", "Mix until blended and fluffy."]
["milk", "flour", "butter", "shortening", "sugar", "vanilla"]