The Nice Big Cake is a cake in Survival 303.
The Nice Big Cake is found in the Cake Cave, which is located in a hidden area on the Plateau Island. The cake is a reference to the video game, called Portal, a game made by Valve where the common message "The Cake is a lie." comes from.
It doesn't respawn, so even if you eat only one portion, it remains like that until it is either eaten further or the server restarts. For some reason, when the candle is hovered over with the eat/drink tool, it shows "Candle" instead of "Cake" although it takes the portions off the cake too.