Effect

A borrowed, marked coin vanishes. Volunteer hands you a biscuit, and you eat up to halfway. The coin is seen in the middle of the biscuit. As the dealer ads. Would say - no duplicates, no fakes, no stooges, no specially prepared biscuits - NO PROBLEMS!

Method

Borrow a coin from a member of the audience and get it marked. Vanish the coin in anyway you like.

I personally like the bobo vanish. Retain the coin in your right hand as you show the left empty. If you have skills, show both hands empty.

(I have customized a changeover palm to work with nearly any object, so try one for you!) With the coin in your right hand, ask the volunteer to give you a biscuit. Take this with your left hand.

Whilst doing this, get the coin in the upper front finger clip. Pass the biscuit over into your right hand resting the biscuit on the coin.

Take the biscuit again with your left hand and press the coin flat against the back of the biscuit.

Take a bite out of the biscuit, and push the coin up the back until it just sticks out the top.

The owner will notice it, and you pull it out and hand it back, then eat the rest of the biscuit, and remove the coin, saying that a filling has come out, and show the coin!