Preheat oven to 375°F.
Make the egg wash.
On a lightly floured surface, carefully unroll each sheet of puff pastry and gently stretch it out all directions using a rolling pin. (one stretch each way is fine)
Cut each pastry sheet into 9 equal squares. Using a teaspoon spread softened cream cheese around the center of each square. Place a small piece (about a teaspoon) of guava paste on top of cheese spread.
Brush around the perimeter of each square with egg wash.
Fold over to make a triangle. Crimp the edges.
Brush every triangle with the egg wash. You can also brush the top of each one for a shiny baked look when finished.
Place on top of a cookie sheet that is covered with parchment paper.
Bake for about 12-15 minutes or until golden brown.
Allow to cool for about 15 minutes and sprinkle with powdered sugar.