Edited.
Graham crackeriness sounds a lot like Vienna and Pilsner malt. Pilsner malt, to me, tastes like honey grahams. Vienna helps take it to another level.
I get nuttiness from English Maris Otter malt, especially if you toast it for a little while in a 350 F oven. It might sound crazy, but I see no reason why if you wanted nuttiness that you couldn't use some percentage (maybe 10%?) Maris Otter, toasted or not, in an Oktoberfest style beer. Or you could try toasting your own German malts to see if it does the same thing.
I'd recommend a good percentage (20-30%) pilsner malt in any Oktoberfest, to make it taste more "German" and preserve some honey-like sweetness. The remainder should be Vienna and Munich, except perhaps as discussed above. My humble opinions.