Avoid using flexible silicone mats to make cannelés if you can help it; I suggest using the traditional metallic (copper exterior) molds, which are expensive but yield the best results.
Introduction To Macarons
First, do not confuse macarons with macaroons. They are two completely different cookies. The macaron is an almond meringue cookie that can be either French or Italian and the macaroon is a coconut cookie that is often dipped in chocolate. Notice also the difference in spelling.
macaron is one of the best items to eat for a sweet fix. It is sweet enough to satisfy with only a few bites, and texturally it is crunchy, chewy, and soft at the same time; even when it is refrigerated for many days it retains the crunch in its outer shell. The variations on flavors and fillings that can be used are almost endless, and this includes savory fillings to an extent. Think of what you are looking for in a macaron when deciding on the fillings you want to use. Use jams, marmalades, fruit preserves, or candied fruits, or you can mix these items with buttercream, for example. Buttercream has the advantage that it can be mixed with many ingredients and it is easy to pipe, but it may mute the flavor you are going for. It also holds very well inside a macaron since it is mostly fat. Using a small quantity certainly does not hurt, but if you can get away without using it, the resulting filling will be a more flavorful product.
The final texture of a macaron with a slightly raised dome with a hard shell and soft interior makes sense. But the thought process behind it is what I find brilliant. The macaron as we know it today exists thanks to Pierre Desfontaines, of the Ladurée pastry shops in Paris. He perfected the recipe and the method, and more important was the first to sandwich two of these cookies together close to the beginning of the 1900s.
There are three key moments in the process that can make or break a macaron:
Folding. At the moment when you fold the meringue into the mixed and sifted almond flour mixture, it is easy to under- or overmix the batter. Getting the mix just right will determine the outcome. Undermixing will yield a chunky, grainy-looking macaron. An overmixed macaron will not hold its shape and will puddle once it is piped onto a sheet pan. A properly mixed macaron will hold its shape after being piped and will have a smooth surface.
Piping. While piping will not necessarily determine the success or failure of the quality of the macaron, it will determine the uniformity of size of the finished pieces. The size is determined not only by the width or diameter of the piped macaron but also by the height at which it is piped. The higher above the sheet pan you pipe the batter, the bigger your macaron will be.
Baking. Baking instructions are provided here, but chances are that they will have to be fine-tuned to your oven, since no two ovens are alike. The most important objectives are to fully bake the macarons and to do so without any Maillard reaction (coloring) on the macarons. Part of the success in this step is letting the macarons form a skin (or shell) on their surface before baking. This occurs after the macarons are piped and left to sit at room temperature to form said shell. This time may vary depending on environmental conditions in your shop. Is it a dry or humid day? Have other ovens been running (is the shop cool or warm)? Is it warm outside or is it cold? Regardless of the environment, you can always judge by touching the surface of the cookie. If it is dry, then they are ready to bake. If your finger leaves a dent or picks up some of the cookie batter, then they are not quite ready. There is also such a thing as overdrying. If the cookie dries for too long, it forms a thick, hard shell, and this will result in no “feet” at the bottom of the cookie. The foot is the grainy-looking belt around the base of the smooth dome. Those feet are a sign of quality in a macaron.