The Hawaiian hot dog served in a bun with a hole punched through the middle is the puka dog.
A puka dog uses a toasted Hawaiian sweet bun pierced lengthwise to create a central tunnel. The sausage is inserted into that opening, while sauces and relishes fill the space around it. “Puka” means “hole” in Hawaiian, which explains the name and the defining construction.
Vendors use a heated rod to make the opening and toast the inside of the bun at the same time. This creates a warm, slightly crisp tunnel and helps keep liquid toppings from making the bread soggy. Common flavor combinations may include tropical fruit, pineapple, mango mustard, garlic-lemon sauce, and other sweet, salty, or spicy condiments.
Puka dogs are sometimes called Hula Dogs, especially in connection with the Hawaiian restaurant businesses that popularized them. The answer is not “bagel dog,” even though both use a hole-like bread format: a bagel dog is a sausage wrapped in bagel-style dough or breading, while the puka dog’s hallmark is the pierced sweet bun.