Article: Shavuos
There is a custom to eat milchigs on Shavuos, and this is certainly appropriate. At the same time, one should remember that there is also a biblical obligation of simchas Yom Tov, which, according to our minhag today, is fulfilled through eating meat.
Cheesecake is one of the most common Shavuos foods. Its bracha is mezonos, even if the crust is very thin, so long as it contains flour from one of the five grains. However, regarding the bracha acharona, one must ensure that a kezayis was eaten.
Practically speaking, since the cheese filling generally makes up most of the cake, it is not always clear how to calculate the kezayis unless the flour constitutes at least one-sixth of the mixture. Therefore, one may not necessarily be obligated to recite Al Hamichya.
The preferable approach is to make sure to eat a definite kezayis of mezonos and a definite kezayis requiring Borei Nefashos separately, thereby avoiding any halachic uncertainty.
Sources:
From Halacha2Go Archives
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