Yong tau foo 酿豆腐 like lei cha 擂茶 are iconic dishes of the Hakka people. The Hakka people originally from the Yellow River basin in central China, migrated south over nearly 2000 years due to invaders from the north (Xiongnu, Mongols, and later Manchus).
Today, Hakka people have migrated across the world and formed the fourth largest Chinese community in Singapore. Everywhere they went, the Hakka brought yong tau foo with them because to the Hakka, "there is no banquet without stuffed dishes" 无酿不成席. At every Hakka celebration, there is yong tau foo on the table.