Nian Gao, Year Cake or Sticky Cake

It is believed that on the Chinese New Year’s eve, Chinese New year gods ascend to heaven to pay their respects and also report on the household chores to the Jade Emperor (玉皇大帝 Yù huáng dà dì), the supreme Taoist deity. A week before the New Year, the Kitchen God (灶神), which watches the family, is offered Nián gāo , Year cake or Chinese sticky cake is a food prepared from glutinous rice. 粘 (Nián), meaning "sticky", is identical in sound to 年, meaning "year", and the word 糕 (gāo), meaning "cake" is identical in sound to 高, meaning "high"). .

So that he submits a favourable report and sealed his mouth from saying bad things about the family in heaven and meets the supreme deity. During the worship, people always say 上天言好事，下界保平安 shàng tiān yán hǎo shì, xià jiè bǎo píng ‘ān – report the good deeds in Heaven, bring the blessing to earth

恭喜发财

The literal translation of “Gong Xi” is “to wish” and “Fa Cai” means “to prosper”.
So “Gong Xi Fa Cai” means “I wish that you will be prosperous”.