This bun is called a Pineapple Bun (菠蘿包, pronounced: boh1 loh4 baau1). Is a bun that is sold in Chinatowns all across the world that originated from Hong Kong. In 2014, it was even listed as a part of Hong Kong's intangible cutural heritage, showing how iconic this bun is. The 'Pineapple' in the name doesn't come from it being in the bun anywhere, but the top simply looking like one. They're often sold in cha chaa tengs (茶餐廳: Hong Kong style cafés) and dai pai dongs (大牌档: Food stall). There are many variations that exist in the world, but they're all equally delicious!