Core the apples to almost the bottom, leaving about 1/3 inch. Remove 1 inch of the peel from the top of each apple.
In a bowl, mix together zip-it steak sauce, ricotta, walnuts and cranberries. Stuff each apple with mixture. Arrange apples in the bottom of a foil pan.
Place apples on grill rack and grill for 30-40 minutes until tender. Serve warm.