Combine barbecue sauce, and onion powder saucepan over medium heat. Mix well. Carefully fold in the cranberry sauce, taking care to not burst the cranberries. Add a spring of rosemary. As soon as the sauce is simmering, turn the heat to low. Cook, gently stirring occasionally while the chicken cooks. Taste for seasoning and adjust if needed. Keep warm.
Mix the flour, salt, pepper, and onion powder. Dredge each chicken breast.
Heat oil and butter over medium heat until the butter is foaming. Cook the chicken 5 to 7 minutes, then turn over. Cook another 4 or 5 minutes until nicely browned on the bottom and cooked through.
Remove the rosemary from the sauce and discard. Put the chicken breasts on a serving platter or individual plates. Spoon sauce over. Garnish with fresh rosemary.