There are various little tweaks and changes to the recipe for these sweet, small yeasted bun depending on where you look. Many Italian recipes specify baking for a very short period—6 or 7 minutes at most—in a very hot oven so that the buns retain their softness. But modern recipes call for baking in a moderate oven for 15 to 18 minutes, which I have found to be a bit more reliable (and they are still pillowy soft). Some include milk, some use just yolks, and most use a sponge (also known as a yeast starter). Although many of today's maritozzi are usually studded with just raisins, traditional recipes, such as the one from Roman cooking queen Ada Boni, also include pine nuts and candied orange peel. If you don't like candied fruit, use lemon or orange zest (or both) instead, fas Carol Field does in her maritozzi recipe in The Italian Baker. (She also has a great use for the water used for soaking the raisins: Add it to the yeast starter.)
You could also skip the glossy syrup top and simply dust with confectioners' sugar before serving. Either way, if you're going to do it properly, the best way to enjoy these is to split them open from the top, leaving the bun attached at the bottom like a hot dog bun and then filling them generously with freshly whipped cream. And your Roman breakfast is ready.
This recipe is inspired partly by Ada Boni's maritozzi recipe in Il Talismano della Felicita and partly by Carol Field's recipe in The Italian Baker. Neither specify the use of whipped cream in the buns, but it is the way you popularly find them in Roman cafés and it is undoubtedly the best way to enjoy them.
Note: You can double this recipe, but double all the ingredients except the yeast, i.e. you only need 25 grams of fresh yeast to make 16 of these buns. If you are using more than one tray to cook these, I recommend baking only one tray at a time and placing it in the middle of the oven. Also, for images on how to shape these buns, this blog post from Bread Cakes and Ale is perfect: https://breadcakesandale.wordpress.com/2013/08/21/maritozzi-con-la-panna-recipe/ —Emiko