Preheat oven to 350 degrees, Combine the flours, salt, baking soda, baking powder, and sweetener together in a bowl. Set aside. Blender together butter, eggs, vanilla, banana extract, starter, and banana until smooth. Grate the pears fine. Add the grated pears and liquid mixture to the dry ingredients. Fold the ingredients together until just incorporated. Pour into a well-greased bread pan. Place bread pan into the oven. Bake for 65 minutes or until toothpick inserted into the center comes out clean. 12 slices.