Remove the dough ball from the fridge about 10 minutes before you will need it. Preheat the oven to 350 F.
Using a hand mixer, beat together the softened 8 ounces of cream cheese and half cup of powdered sugar. Add this mixture to a pastry bag fitted with a circle tip. Set aside while you cut out the circles. Cut the guava paste into small rectangles, not too thick. They need to fit inside the circles.
After about 10 minutes, roll the dough out onto a floured work surface. Using a cup with a roughly 3-inch diameter opening, cut out the circles. Line two baking sheets with silicone baking mats or parchment paper.
Lay the dough circles evenly on the baking sheets. Put 1-2 pieces of guava paste on each circle. Add some sweetened cream cheese onto the guava paste. Fold the dough around the guava and cheese mixture, covering all of the filling. Press the edges together. The end result should look like mini empanadas.
Repeat this process until all of the cookies are made. If you want to make the heart-shaped pastelis, you'll need some heart-shaped cookie cutters. Cut out an equal number of larger hearts. Then, using a small heart-shaped cookie cutter, cut out a small heart from half of the hearts. Place the guava and cheese on the whole hearts and top with the cutout heart.
If desired, top with large crystal turbinado cane sugar. Bake one sheet of pastelitos at a time for 20 minutes at 350 F.
Let the pastelitos sit for 10 minutes before enjoying. They will be hot! They are so delicious, you won't be able to stop at one!