You can work use this several different ways.
First take a Cool Whip container and spray paint it with the type of spray
paint that adheres to plastic. White paint would be more appropriate
but red paint was all that was available around here. After it has dried,
take an Exacto knife and "drill" holes in the top. You can put circle
stickers or other stickers on it to make it look like a cake.
You can give the children candles and have them put them in the holes
to make the cake.
You could write a number on the front of the cake and have the children
put the corresponding number of candles in the cake.
For young children, you can write a number on the container and "drill"
the same number of candle places on the container.