Anonymous wrote:OP here, thanks for the suggestions. I was in a time crunch so I took a leap of faith and bought a can of the Duff Goldman white frosting. Fits the bill - not as sweet as most of the canned ones and doesn't seem to have that same chemical taste. It will be fine under the layer of berries.
I was going to suggest Duff! Just saw his stuff was available. I bought some of his cake mixes and fillings (lemon, raspberry) but haven't tested them out yet. Let us know your verdict once the guests all taste!