Pulled Barbecue Chicken Sandwiches

1. For the chicken, preheat the oven to 375˚F. Line a baking pan with aluminum foil and coat with nonstick spray.2. Arrange the chicken breasts in the prepared baking pan and drizzle the olive oil all over the top; season with pepper. Bake the chicken until barely pink in the center, about 40 minutes.3. To make the sauce, put a pot over medium heat and coat with the oil. When the oil is hot, add the onion and garlic. Cook, stirring, until soft and fragrant, 2 to 3 minutes. Stir in the tomato paste until fully incorporated. Stir in the vinegar, loosening up any brown bits on the bottom of the pan. Add the tomato puree, ketchup, Worcestershire, sugar blend, paprika, mustard, chili powder, and water. Bring the barbecue sauce to a simmer, stirring, and then reduce the heat to low and simmer gently for 20 minutes, until the sauce is slightly thickened.4. Allow the cooked chicken to cool slightly, then peel off and discard the skin. Using 2 forks, shred the meat and discard the bone.5. Add the shredded chicken to the sauce and stir to incorporate. Simmer for another 5 minutes, until heated through. Divide the chicken among the buns and serve.