Although cakes and cookies bake at the same temperature, about 350 degrees, cakes reach internal temperatures of only around 210 degrees. But cookies, which are small and thin, will exceed temperatures of 280 to 300 degrees. At high heats, all the hundreds of wonderful flavor chemicals of natural vanilla burn off. The result is that your vanilla sugar cookies, baked with natural vanilla extract, end up virtually tasteless. But imitation vanilla, which contains pure vanillin, delivers a much more potent dose of flavor that survives the oven's heat.

— Eight Flavors by Sarah Lohman (Page 48)