This is The BEST frosting in the world!! I thought I lost it recently and was not able to find it anywhere...THIS is the recipe you're looking for!

1/4 cup flour
1 cup milk

Combine in saucepan, cook over medium heat. Keep stirring or it will lump. Bring to a boil and it will get thick like glue. Let it COOL COMPLETELY!!

After completely cool add:
2 sticks Fleischmann's original margerine COLD (this was VERY specific, and I ALWAYS use this!!)
1 cup granulated sugar
2 teaspoons vanilla

Beat for 10 minutes or more until it turns fluffy. Then frost.

My aunt always froze her cakes first - then frosting it while still frozen...