I'm doing a snack trade with an American friend and I don't know what to ask for since there's a pretty heavy...

birch beer (which is just a soda) and maybe some jerky (not jack links) or pretzel cheese combos

the midwest

I'd be down for some spice mixes or obscure chips.
I want to avoid any soda from the US because it's readily available here and it's made with HFCS. A lot of stores import Dr. Pepper from the UK and it tastes infinitely better.

We have cane sugar Dr. Pepper too, it just costs a few cents extra.

Walmart thin mint cookies. They taste just the same as the shit girl scouts sell.

Well, right now there are about 1000 pumpkin spice products in the US, from cereal bars to flavored coffee mixes to cookies. Add to that the halloween versions of candy bars or peeps, or such. There's good stuff to be found at a Walgreen's for novelties like candy corn in 15 flavors, and jellied eyeballs for gummies, big creamy reeses pumpkins. Christmas limited edition candy is next. Nerds ropes are craveable!
In a good grocery, there are some oddities in the snack chip aisle from veggie sticks, hollow pretzels, 7 layer dip Combos, weird flavors of beef jerky like lemongrass or bacon. There are new muddy buddies in Chex Snack Mix, even some that are drizzled with reeses and caramel popcorn in there. The salt with lime Orville microwave popcorn is my favorite. The smokehouse almonds or new bold flavors are yummy and part of my road trips. They make good crackers too.
S'Mores poptarts are best flavor. Graham crackers are a US thing and part of that recipe, so maybe they could send you a Smores kit really.
Weird flavor Lay's are like 4 a season. Most are horrible, LOL. I like maybe 1 out of 4 each season, and would never buy again. There are some good tortilla and potato chips flavors out now, though. Your preference varies.
Smuckers boysenberry syrup or jam, palmetto hot pepper jelly, Howards hot piccalilli
Dark grade B maple syrup can be sublime to cook with, like for granola, or melt-on-your-tongue maple sugar candy if expensive for you or you can't get that specifically
black walnuts
regional honey like key lime or lychee or mango or avocado or blackberry honey if they can find it for you at a local farmers market. Avocado honey is buttery and luscious with fresh cheese
Some hispanic food can be hard to find: instant masarepa flour, goat cajeta or candies, or chili-mango lollipops, drink mixes like guanabana or guayaba, or spiced atole or colombian hot chocolate with piloncillo sugar like LUKER brand.

How cheap/common is bulk peanut butter? I have relatives that always stock up on it whenever they visit me in the states.

Mexican goods are also fairly common in the US that might not be as easy to get a hold of elsewhere.

pork rinds
red hot blues corn chips
pizza combos

this is the full experience

A&W root beer

If your friend is from the South then ask for Zapps Voodoo chips. The best damned chips you'll ever have.

Andy Capp's Hot Fries

this

Wheres he live right now? If youve got a saturation of american snacks then hed have to find something more localized.

Im in south florida and id recommend platano chips.

Fuego Takis.
Tamarind candy
Pork rinds

Basically just have him go to a Mexican grocery and get a bunch of good shit. Get some El Yucateco hot sauce. Mexicans got snacks for days. American snacks are great but you can get em anywhere already.

Maybe some good bbq sauce? I'd recommend Head Country, but it's not available everywhere.

Where are you from btw and what are you sending Ameribro?

Pic
Necco Wafers
Flamin Hot Cheetos
Pork Rinds

Which state?

Euro in Ameriland here.
My country doesn't have many American products. Family who have visited have all rather enjoyed Reese's Pieces so I used to send that from time to time but with online sales being a thing, there's no reason for me to do that anymore.
Basically, there's likely nothing you can ask him to ship you that you can't find yourself online. The point of these package exchanges, IMO, is to try shit you wouldn't choose on your own. Just let him pick your stuff without your input and send you the package.

Birch beer is wonderful.

Pure maple syrup

Oh and I see it's been said a few times. Fucking pork rinds are awesome (lots of protein too, if you are into that)

what an impressively bad mix of candy.

no he isn't lying, swedish fish are amazing

Even root beer? Most of the time I talk to foreigners they've not heard of it.

Because sassafras is more commonly used in Euroland to flavor toothpaste instead of mint. When they try root beer, quite a lot of them tend not to enjoy it because it is very sweet and reminds them of drinking toothpaste fluid.

Everyone said pork rinds already but see if they can send plain as well as salt and vinegar. S&V pork skins are like sex. Also, Slim Jim. Snyder's Pretzel pieces (especially the flavor pictured) are fucking wonderful too.