The Quantum Cookbook provides a unique bridge between popular exposition and formal textbook presentation, based on derivations of the iconic equations of quantum mechanics. This is a book for curious readers with some background in physics and sufficient mathematical capability. It aims not to teach readers how to do quantum mechanics but rather helps them to understand how to think about quantum mechanics. Each derivation is presented as a ‘recipe’ with listed ingredients, including standard results from the mathematician’s toolkit, set out in a series of easy-to-follow steps. The recipes have been written sympathetically, for readers who—like the author—will often struggle to follow the logic of a derivation which misses out steps that are ‘obvious’, or which use techniques that readers are assumed to know. The simple truth is that quantum mechanics did not suddenly materialize overnight in the minds of its creators, fully formed, complete with all its axioms and principles. It was instead tortured from much more familiar classical physical descriptions, over a period of decades, as physicists struggled to interpret a series of ever more baffling experimental results. Only later was a much higher level of abstraction introduced into quantum mechanics, in an attempt to establish a secure mathematical foundation that would eradicate all the confusing classical misconceptions inherited from its birth and early childhood. Whilst there are some obvious exceptions, for the most part these derivations are triumphs of physical intuition over mathematical rigour and consistency.