Totally unreal @nickweinberg and thanks @chris101 for your sweet comment
@blindbento: the cakeBit had a 3 layer PCB. The top and down layers where vanilla flavor with chocolate chips, and the middle layer was a mix of chocolate and dulce de leche. The white superficial color of the PCB, and the typography is chocolate, and the bitSnaps are made from a sugar thing, the same material of the leds. The rest of the components (metallic type) are not comestible.
One funny thing were the candles: there were no candles! Instead, we used 3 littleBits circuits consisting of a power, a button, and a bargraph. 3 volunteers pressed the buttons during the happy birthday song, and at the moment of blowing the candles, they released the buttons, turning off the lights