These delicious pastries filled with guava and sweetened cream cheese are of cuban origin, but you can find them in many latin bakeries. They are particularly popular in miami. Of course, you can make homemade puff pastry dough if you enjoy doing so, but frozen puff pastry saves a lot of time. Another shortcut is to make the pastry in one long strip, then slice it into individual portions after it comes out of the oven. This saves you from cutting out many individual squares of pastry (bakeries use this trick as well). You may be able to find guava paste, which is more solid than the more readily available guava jelly, so it doesn't tend to spread and leak from the pastries as much. But either one will work. One for making your pastelitos look and taste just like the ones from the bakery is the simple sugar glaze that is brushed on them halfway through baking-it's an extra step, but the result is worth the time.