Blend the cream cheese, butter and flour until well mixed. Wrap in plastic wrap and refrigerate for at least 30 minutes.
Preheat oven to 375 degrees F.
Roll out the dough into a 1/4-inch thick square. Cut the rolled dough into 16 to 20 squares.
A little off center of each square, place 1 tablespoon guava paste. Fold the dough over the guava paste, forming a triangle. Press the edges shut. Place the pasteles onto a cookie sheet and sprinkle them with a thin layer of sugar.
Bake until the pasteles are evenly browned, about 25 minutes.