coffee peanut butter sheet pan dessert...what size pan?

I assumed from the recipe that this is made in a "jelly roll" pan. Can it be made in a 9"x13" pan instead, if I cut the recipe in half? It is a lot of ingredients to use if we find we don't like it as much as I think we will. Also, what exactly is the "nut crunch" from Baker's Choice? The ingredients I saw said it contained coconut? Can I just put chopped nuts on top? It really sounds like a great recipe, and I am looking forward to making it.