Personally, I like cheese and maybe summer sausage or pepperoni with a couple of crackers. Yes, the crackers add a bit of normal carbs, but I only eat about 4, sometimes 6 crackers with a thin slice of cheese and a thin slice of the meat to go with it. Yes, it is higher in fat, but that is typically the main fat content I get throughout the day, so it is actually minor in comparison. The advantage here is the cheese and meats are higher in proteins which take longer to digest so it balances out overnight for me a bit better. I do have to watch what type of pepperoni or summer sausage I eat as if it is a bit spicy, well then I will have weird dreams... but good cheese well, that is heat warming for me. I like Cooper, typically sold as a sliced lunch type or sandwich type of cheese sold at a deli department, even Walmart deli has it. OR a really good cheddar that has NOT had yellow food coloring added. A good cheddar is always white in color. I have never figured out why Americans insist on adding yellow food coloring to cheese... must be Kraft that has caused that. After all, everyone is exposed to Kraft brand American Cheese which is always yellow unless you specifically look for the natural white.
Regardless, that small snack, about the size of the little cheese cracker packs you can get at a convenient store, is just about perfect for me. I prefer either plain saltines, or maybe one of the varieties of snack crackers, Ritz for instance, unflavored, just naturally baked stuff...
For me, for some reason, PB had a bad effect on me. Peanuts in general actually, tends to cause a spike in Bg then a rapid lowering. Usually meaning I end up in a low Bg reading after a couple hours, so, counter productive to use as a night time snack.
Fruit for me has always been a negative, again due to Rapid rise and then very rapid lowering of BG. Too high, too fast, then drops very quickly as it is burned off OR just generally unsatisfying. I love apples, don't get me wrong, I eat them with a sandwich etc, but not at night as the BG rise is much to high to properly counteract with bolus as I can never seem to adjust for fruit sugar correctly.