Preheat oven to 400 degrees. Spray baking sheet with cooking spray. On a working surface, separate and lay out each of the disks. Place 1½ tablespoons of the guava paste and 1½ tablespoons of the cream cheese in the center of each of the disks. Break the egg and separate the yolk into a small dish – white can be discarded. Add 2 tablespoons of water and mix with the yolk. Brush the bottom edge of each disk with the egg wash. Fold the bottom half of the disk up until the edges meet and seal with a fork by pressing down to form ridges. Next, gently transfer each empanada onto the baking sheet, leaving 2 inches in between. Lightly brush the top of the empanada with egg wash. Bake in the middle of the oven for 11-12 minutes or until lightly browned. Serve warm or at room temperature.