A degree or certificate definitely help, but it's not a requirement, if you are able to get your foot in the door of a place that is willing to teach you the basics. The great thing about a good culinary school is that you leave there with an understanding of the essential concepts and formulas in pastry (mostly the science end of it), and it's a good springboard to an assistant's job that may otherwise take you a longer time to get. If you've been to school, it is automatically assumed that you know how to use ingredients, or follow a standard formula. As a pastry chef, I find it easier, in general, to train and work with culinary school grads, because I don't have to explain every little thing to them.