I just got off the phone with a Hostess CSR, she was very, very sweet.
I initially called about their cream cheese danishes, but ended up getting a lot more answers.
Safe Codes:
2520, includes Cinnamon Rolls and Cream Cheese Danishes.
Also safe codes: 2400, 2510, 8500 (bread), and 8400 (bread).
UNSAFE Codes:
8800, 8830, 8880, 2300, 2100.
I didn't have a code for the new Halloween cupcakes, but was told they are not safe (bummer!). I'm feeling festive, but as long as I get to try the cream cheese danishes, I think I'll get over it.