Q. Can one buy with Maaser money cakes or other foods for Yom Tov that are sold for the benefit of an institution like a yeshiva?

A. Horav Shlomo Miller’s Shlit’a opinion is that you would have to deduct the market value of the food, and only the amount that actually reaches the institution can be contributed from Ma’aser funds,

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a