Preheat oven to 375 degrees F.
Slice (butterfly) 4 chicken breasts horizontally about ¾ of the way through each breast. Do not fully slice breasts in half. The chicken breasts should be cut like pita pockets that will be filled later with the cheese mixture. Set chicken breasts on a plate and set aside for now.
Spray a 9” x 13” baking dish with non-stick cooking spray.
In a medium bowl, stir together olive oil, salt, black pepper and garlic powder.
Place chicken breasts in olive oil mixture (one at a time) to fully coat both sides of every chicken breast. As each is coated, place the chicken breasts in the prepared baking dish.
In a medium bowl, beat together cream cheese, shredded cheddar, crumbled bacon, ¼ cup of the buffalo sauce, mayonnaise and dry Ranch seasoning until fully combined.
Gently spoon mixture into the middle of each chicken breast. Distribute filling evenly in each of the 4 chicken breasts.
Bake in oven for 40 – 45 minutes or until chicken is thoroughly cooked. Use a meat thermometer to make sure chicken internal temperature has reached 165 degrees F. Check the middle of the thickest part of the breast (not into the cream cheese filling) for an accurate temperature reading.
With 5 minutes left of baking time, remove baking dish from oven and top chicken breasts with the remaining ¼ cup of buffalo sauce. Return baking dish to oven for the remaining 5 minutes.
Remove baked chicken from oven and serve hot. Drizzle Ranch dressing over chicken and sprinkle with green onions (optional).
Store leftovers in a sealed food storage container in the fridge for up to 3 days.