When crafting a cake, all the ingredients used get consumed by the cake.

3 buckets of milk

3 wheat

2 sugar

1 egg.

The cake itself then disappears and never existed. 

Funny enough, one empty bucket remains. The reason explained below.

A possible lead to this bug comes from a disappearing milk bucket when more than two 

milk buckets are stored anywhere. This includes crafting table, storage boxes, except when held in the inventory. However when taking damage, milk also disappears. 

To be clear:  The bucket itself remains. The content itself disappears