Preheat Blackstone griddle to medium heat. Add bacon and cook for 5 minutes. When the bacon has started rendering out fat, add the chicken and green bell peppers. Season with salt and pepper. Cook for 10 minutes until the bacon is very crispy and the chicken is fully cooked
Drizzle vegetable oil onto the griddle then lay out 4 tortillas. Top with shredded cheese then evenly divide the chicken bacon mix between the 4 tortillas. Divide the ranch between the 4 tortillas, top with cheese and the remaining tortillas.
Flip the quesadillas and toast on both sides until crispy and golden brown. Remove from the griddle, slice, and serve immediately.