 My personal favorite part of birthday celebrations is the cake. One theory about the origin of birthday cake is that it originated with the Greeks, who baked round cakes representing the full moon for their moon goddess. They placed candles on the cake to make it glow, like the moon. The Germans are also credited with the first cakes and candles. They used a sweet layered cake and they put a large candle in the center of the cake to represent the light of life.