Prepare the chicken. Cut the chicken breasts into approximately 1½-inch pieces, keeping them as uniform as possible so they cook evenly.
Make the Caesar marinade. Add the Ken’s Caesar Dressing, fresh lemon juice, minced garlic, red pepper flakes, salt, and black pepper to a large bowl. Stir to combine.
Marinate the chicken. Add the chicken pieces to the marinade and toss until completely coated. Cover and refrigerate for at least 30 minutes.
Prepare the skewers. Preheat the grill to medium-high heat. Thread the marinated chicken pieces onto skewers, leaving a small amount of space between each piece. If using wooden skewers, soak them in water for at least 30 minutes before assembling.
Grill the chicken. Place the skewers on the preheated grill. Grill for about 10–12 minutes, turning every few minutes, until the outside is lightly charred and the thickest pieces of chicken reach an internal temperature of 165°F.
Make the garlic Parmesan Caesar sauce. While the chicken grills, combine the melted butter, Ken’s Caesar Dressing, minced garlic, Parmesan, parsley, and red pepper flakes in a small bowl. Stir until well combined.
Brush with sauce. Remove the cooked skewers from the grill and immediately brush them generously with the garlic Parmesan Caesar sauce while the chicken is still hot.
Finish and serve. Sprinkle with additional Parmesan and fresh parsley, if desired. Serve immediately.