"Them dirty boys turn your pound cake to Red Velvet" - 'Kast

Apparently this is the move for RV frosting according to some folks over @ Chowhound

3 - 5 Tbsp flour

1 cup milk
1 cup butter or margarine
1 cup sugar
1 Tbsp vanilla

Cook flour & milk until thick, whisking constantly. Take off heat & lay plastic wrap over the surface to prevent a skin from forming; cool in refrigerator. Cream together sugar & butter/margarine. Add cooled flour mixture & vanilla & beat with electric mixer for a long time (10min) ntil fluffy.