Preheat your oven to 375°F (190°C).
In a large mixing bowl, combine the shredded chicken, cheddar cheese, cream cheese, sour cream, garlic powder, onion powder, salt, and black pepper. Mix until well combined.
Unroll the crescent roll dough and separate it into triangles.
On a baking sheet lined with parchment paper, lay out the triangles with the wide end facing you.
Spoon a generous amount of the chicken mixture onto the wide end of each triangle.
Fold the sides of the triangle over the filling, then roll it up from the wide end to the point, sealing the filling inside.
Place the foldovers on the baking sheet, seam side down. Brush the tops with the beaten egg for a golden finish.
Bake in the preheated oven for 15-20 minutes or until golden brown.
Allow to cool for a few minutes before serving.