Conversation so far:
who invented the first peanut butter and jelly sandwich
The first located reference to the now immortal peanut butter and jelly sandwich was published by Julia Davis Chandler in 1901.
what kind of variations of the peanut butter and jelly sandwich are there
Some variations for the PB&J sandwich include substituting honey or sliced fruit for the jelly component. Marshmallow fluff can also be substituted for the jelly or added.

Question: what kind of jelly is most common
Self-contained rewrite: what kind of jelly is most common in a peanut butter and jelly sandwich