Should a pan of brownies really be called "brownies" if uncut and in one piece?
I have never heard anyone call a pan of brownies anything other than a "pan of brownies".
Thinking about this, I realized that there is nothing plural about a pan of brownies. Is it just that everyone assumes it will be cut and refers to it as such?
Solution 1:
Yes, I don't see anything wrong with this. It's multiple brownies, but they're just not cut yet. Another similar situation is with cocktails; you might say "I made mojitos!" even though they're all together in a pitcher.