u003cbr/u003eThe hole in the center of a vadai serves both functional and culinary purposes. Functionally, the hole helps the vadai cook more evenly by allowing heat to penetrate the center, ensuring the interior is cooked thoroughly. u003cbr/u003eu003cbr/u003eu003cbr/u003eThe hole helps create a distinct shape and texture, with a crispy exterior and a soft, fluffy center, making the vadai more enjoyable to eat. Having the hole also creates a higher ratio of crispy outside to fluffy inside.