Tiramisu, AKA Tuscan Trifle, is a traditional Italian dessert which may have originated in Siena, which is a north west Italian province located in Tuscany. When my mother visited Italy years ago, back in the late 1980's, she was introduced to this wonderful dessert at many of the various restaurants she dined in. Each town she and her companion visited had its own variation of this incredible dessert.
If you are having trouble finding the mascarpone cheese you can substitute cream cheese. Classic tiramisu is made with lady fingers which I can not locate in my local grocery stores. The margherite cookies make an acceptable substitute.
A classic recipe for tiramisu can be found in my article Traditional Italian Meal. I have come up with this recipe as my salute to this traditional Italian treat. In recent years this treat has been adapted into a variety of other desserts including cake, cookies and puddings. My local Costco even sells a chocolate flavored tiramisu, although my husband and I don't enjoy it as much as the traditional recipe.
Information on the history of tiramisu can be found on the What's Cooking America and Anna Maria Volpi websites. See the article The Many Culinary Uses of Cinnamon for additional information on cooking with this spice.