年糕 - 年高 every year higher and higher

Nian gao, Rice cake, Year cake or Chinese new year's cake is a food prepared from glutinous rice and consumed in Chinese cuisine.

 It is considered good luck to eat nian gao during this time because "nian gao" is a homonym for "every year higher and higher." 年糕 - 年高

While traditional Nian Gao is steamed and does not contain butter, eggs or other ingredients normally found in a cake batter

During the Spring Festival period or Chinese New Year, 

the northerners China people prefer to eat Jiao Zi, 

but southerners’ people like to eat NianGao, 

Nian Gao literally mean Year Cake or Chinese new year's cake is made of glutinous rice.

 Traditionally Nian Guao is the main Chinese New Year cuisine;

 it is considered good luck to eat Nian Gao during this time. 

In Chinese, Gao is a homonym for high. Nian Gao is also called Nian Nian Gao, which is a homonym for "higher each year", 

symbolizing progress and promotion at work and in daily life and improvement in life year by year.

The Kitchen God is fed with a sticky New Year cake to ensure that if Kitchen God speaks ill of the family in Heaven, the gluey cake would stick his mouth. 

This tradition seems to be quite an implicit pact between the Kitchen God and his devotees. 

According to various accounts this cake was given either as bribe, or simply a means of ensuring the Kitchen God's mouth was too full of cake to submit an unfavorable report in the Heaven.