Preheat oven to 400°F (200°C).
In a large zip-top bag, combine mayonnaise and ranch seasoning. Add chicken breasts and coat evenly. Seal and refrigerate while preparing vegetables.
Grease or line a large baking sheet with parchment paper.
Place potatoes and carrots on the pan. Drizzle with olive oil, then season with salt and pepper. Toss to coat. Arrange potatoes cut-side down and push vegetables to the sides.
Place bread crumbs in a shallow bowl. Remove chicken from marinade, shake off excess, and coat in bread crumbs.
Arrange chicken on the baking sheet with a small space between each piece. Lightly spray with oil if desired.
Bake for 25–28 minutes, or until the internal temperature reaches 165°F (74°C).
Broil for 2–3 minutes to achieve a golden crust.
Garnish with parsley and serve warm.
This one pan chicken and vegetables recipe ensures crispy, flavorful results every time.