i am making a chocolate peppermint cake but i don't know how much peppermint extract or peppermint oil to add to the batter? it is enough batter to make 30 cupcakes or 1 ten inch round. thanks so much!

I think how much you use would depend on the brand and type of peppermint you are using. I would put 1/4 tsp in your batter and after mixing it take a small taste. Peppermint is one that to me gets stronger and can be too much. If you do not think it is minty enough you can certainly add a little at a time until it is agreeable to you. It is better to add more than to have too much in your batter and of course, no way to remove it.