I am making a wedding cake. Typically, I use buttercream to fill and ice the cake. A week prior to the wedding I freeze my non-iced tiers with bc filling between the layers. The day before the wedding I defrost the tiers and ice them and put the cake together.

For this particular wedding, the bride and groom want frosting based on the groom's grandmother's recipe. I successfully made a practice cake(no freezing involved) for them and they loved it.

Now, that that time is drawing near, I am wondering if there are any problems with freezing this type of icing/frosting. The recipe is below:

FROSTING
1/2 cup All Purpose Flour
1-1/2 cups milk
1-1/2 cups sugar
1-1/2 cups butter or margarine, softened
1 tablespoon vanilla

In medium saucepan, combine flour and milk. Cook over medium heat until mixture is very thick, stirring constantly. Cover surface with plastic wrap; cool 30 minutes or until completely cooled. In large bowl, combine sugar and margarine; beat until light and fluffy. Gradually add flour mixture by tablespoonfuls, beating at high speed until smooth. Beat in vanilla.

Thanks!

Just for clarification, this icing will be frozen as the filling. I will ice the cake after I thaw it out.

I don't see why not. You can freeze just about anything. Maybe after freezing it, let it thaw in fridge overnight?