It makes sense to me. You can ask a Casanova this question.颗糖 here reminds me of 颗心 . Does "你有几颗心?" make any sense in Chinese (figuratively) ?
Ah, thanks for enlightening me. The 量詞 sometimes give me trouble. I suppose I had a misconception that 一顆 something would be round-ish (蘋果, 心) and 一粒 would generally be small (米, 沙)。This explains why we rarely say "幾塊糖" when referring to sugar cubes. While it is not wrong, it sounds coarse/unrefined to my ears.
I guess that's why I mistakenly thought it would apply to square-shaped sugar cubes.块, to me, would usually refer
eto things of a bigger size than 颗, and also for things that are generally square or rectangular-shaped...