Preheat oven to 375°F (190°C). In a medium mixing bowl, combine the cream cheese and cream of bacon soup. Use an electric mixer to blend until smooth.
Stir in shredded mozzarella cheese and bacon bits. Set aside.
Horizontally slice the chicken breasts to open them up. Spoon the cream cheese mixture onto the bottom halves of the chicken.
Fold the top halves of the chicken over the cream cheese mixture and place in a greased 9×13 inch baking dish.
In a small bowl, beat the egg well. Brush the beaten egg over the tops of the chicken breasts.
Sprinkle the crushed Doritos over the chicken, pressing them down to adhere to the egg wash.
Bake for 33 minutes, or until the chicken is cooked through. Allow the chicken to rest for a few minutes before serving.