What makes chocolate chip cookies come out flat instead of puffy?

Question by goober: when making chocolate chip cookies, what makes the cookie come out flat instead of puffy?
My family loves chocolate chip cookies home made. Is it the baking power or baking soda that makes them come out puffy as opposed to flat?

Best answer:

Answer by Hammy H
Baking powder makes the cake or biscuit rise. If you are using self raising flour, then you don’t really need it because it has it in already, but you can add extra if you really wanted to.

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