Add just a little bit of the spice to your next sweet and tart key lime pie, and you'll taste the difference. Read more: 30 Types Of Cake, Explained A little cinnamon always goes a long way -- and ...

For Allen, the ultimate key lime pie filling ingredients are a well-kept secret, one she's guarded since she began making the pies in 2010. The only ingredient the self-taught baker will divulge ...