The first written record about cannelloni is mentioned by Gio Batta Magi from Arezzo, who mentioned it among his Tuscan recipes. However, it is said that their birth occurred shortly afterwards in Campania, more or less in the first half of the nineteenth century. At the time the Neapolitan cook Vincenzo Corrado mentioned in his book "The Cook Galante" the recipe for a large pacchero , first boiled and then filled with a stuffing made with meat and truffles and then covered with a meat sauce and baked. Although the invention of the cannelloni remains uncertain and although there are few writings and cookbooks of the time that referred to it, it is assumed that this was initially a poor dish and a collection of leftovers , consumed especially during the holidays.
Having thinner sauce and lightly browned beef is very important in this recipe as we need liquid to cook the cannelloni. Try to find balance and make sure your sauce is not too thick but also not too thin, somewhere in middle.
Best way to fill your cannelloni is directly in the baking dish. Place them vertically and simply fill them with spoon. Make sure to get baking dish with perfect fit for amount of cannelloni you make. It's better to have smaller baking dish than larger as you can always put cannelloni on top of each other. Cannelloni have to be completely covered in ragù otherwise it will not bake and pasta will dry out.