Preheat oven to 400 degrees F. Slice the spaghetti squash in half, lengthwise from root to end. Remove the seeds and brush the insides with olive oil. Place cut-side down onto a prepared baking sheet with parchment paper (or foil). Roast for 35-40 minutes, or until it feels tender when squeezed or when easily pierced with a fork or knife. Time may vary depending on the size of the squash.
When squash is removed, lower oven temperature to 350 degrees F. While the squash is roasting, prepare the chicken. You can use pre-cooked chicken or follow the instructions to cook below.
Place a large nonstick pan over medium heat with 1 tablespoon of olive oil. Season the chicken breast (that is thinly sliced - will cook faster and evenly) with salt, pepper, garlic powder, and onion powder. Cook 3-4 minutes per side or until the internal temperature reaches 165 degrees F. Remove to a plate to cool slightly before shredding with two forks.
To the same pan, add 1 tablespoon of olive oil and saute the diced peppers and onions until the onion is translucent. Add the minced garlic to cook for 1 minute. Remove from heat.
To a large mixing bowl, combine the sautéed peppers and onions, shredded chicken, 1/2 cup of shredded mozzarella cheese, Frank's RedHot Buffalo Wing Sauce, cream cheese, and greek yogurt. Mix thoroughly to combine.
Once the squash has been cooked and cooled enough to handle, use a fork to scrape along the edges to create strands. Remove approximately 1/2 of the squash from each bowl and fold it into the buffalo chicken mixture. Be careful not to pierce or tear the shell of the squash.
Stuff the spaghetti squash skins with the mixture and top each squash with the 1 cup of cheese (1/2 cup per squash) and place face-up onto the same baking sheet. Bake for an additional 10-15 minutes, or until the cheese has melted.
Optional: Switch the oven to broil on LOW for 2-3 minutes to brown and crisp up the the cheese slightly.
Garnish with pepper, chives, and your favorite ranch or blue cheese dressing.