1. Preheat oven to 350 degrees Fahrenheit (180 degrees Celsius).
2. In a large bowl, cream margarine and sugar until light and fluffy. Add eggs one at a time, beating well after each one. Beat in the vanilla.
3. Combine the flour, baking powder, baking soda, and salt. Add to the creamed mixture alternately with the non-dairy sour cream until combined.
4. In a separate bowl, combine pears with cranberry sauce. Fold into the batter.
5. Pour batter into a greased and floured 10-inch fluted tube pan. Bake for 50 minutes or until a toothpick inserted in the center comes out clean. Cool 10 minutes before removing from pan.