This special Icelandic bread is buried underground to bake. Hverabraud of “volcano cake” is cooked by the heat from geothermal springs. According to BBC, once the dough is mixed together it’s put into a pot and wrapped thoroughly so the hot springs water won’t get in. Then a hole is dug in the sand approximately 12 inches deep, the pot is placed inside and the hole is covered up.
It’s then left for 24 hours, unearthed, and the amazing rye bread is revealed. The cake is dense, chewy and a little sweet. Hverabraud means “hot springs bread,” but it's also known as thunder bread. Some say this is because eating too much of the high-fiber rye can make you thunderously gassy. Others say it’s because the bread is served at a special viking festival to honor Thor, the God of thunder.
The baking tradition dates back centuries, when Icelandic homes didn’t have stoves. They had to cook flatbreads on an upturned pot over a fire. Once leavening agents were introduced in the mid 18th century, the rye bread quickly became popular throughout the country, where it’s eaten with butter or pickled herring. Now, the bread could be baked in a modern oven, but if you have a hot spring handy, you could also have fun making it that way.