Top 100 Five-Ingredient Dinners

Food.com is not letting me post replies. This is for Railmom. The photo is by someone else, not the recipe contributor. Anyone can post a photo, the recipe contributor has no control.

The cake and the filling worked out well. However, I had never made an icing like this (I usually do some type of cooked buttercream and never had a problem); I followed the recipe instructions and cooked it over a double boiler, and it never got thick enough and just ran down the cake. Was it supposed to be chilled first before attempting to ice the cake?