In ep.#166 "The Strike", Kramer makes a discovery on his first day back at the bagel shop. I believe his statement is to the effect of "raisins baked right into the dough - what'll they think of next!"
However, Kramer has already had prior experience with this phenomenom as evidenced earlier in ep.#155 "The Muffin Tops", as he has given one of his Peterman Reality Tour patrons a pizza-topped raisin bagel, (and a pizza donut for Jerry).
--JKB