In a saucepan over medium heat, melt the butter. Add the sugar and stir to blend. Reduce the heat to low and cook until the sauce begins to darken slightly, stirring constantly. Add the flour, whisk to blend, and continue stirring until well mixed. Add the vinegars and stir until the sugar dissolves. Bring the liquid to a slow boil and cook until it is reduced by half, about 15 minutes, and thickens. Remove the pan from heat and stir in the raspberries and Chambord.

Preheat the oven to 350°F. Lightly grease a large baking dish. Using tongs, dip the browned chicken pieces in the sauce and arrange them in the baking dish. Bake uncovered for 20 minutes, or until the chicken is tender. Reheat the remaining sauce on low heat and serve with the chicken.