Flatten chicken breasts by placing meat between two pieces of plastic wrap. Starting in the center, pound chicken with a mallet or rolling pin to an even thickness.
Thoroughly mix ketchup with cranberry sauce, sugar and allspice.
Heat oil in a large skillet over medium high heat. Brown chicken for 2 minutes on each side then reduce heat.
Pour sauce mixture over chicken in skillet. Cover and simmer 4 minutes, stirring occasionally. Turn chicken; simmer an additional 5 minutes or until chicken reaches internal temperature of 165 degrees F (74 degrees C) or is cooked through.
