Commerial-grade packaging (long shelf-life) for my cookie-like pastry
Firat, first, first : look at your local rules and regulation regarding selling food product in your area.
First first : Decide how long you want to have your product to last, this will put restriction on packaging.
First, you need to do a lot of testing with different kind of packaging and see how your product behave over days, weeks and months (whatever long you want to keep the product)
Find a local food laboratory to test your product for safety (bacteria, mold.... ) at different days, weeks...
If/When the product is safe to eat, you also need to test the product to see if it is still good (not stale, loss of flavour...)
After that, look for different packaging solution for your product, most packaging can be done in-house (heat sealed) so you can buy custom printed bags or pouches (for example for granola melange) or paper packaging (for example for chocolat bars)
I've googled for &quot;commercial food packaging&quot; and there are many solutions for this, just look it up.