Heat oven to 350 and lightly grease and flour two 9-by-5-inch loaf pans.
Combine the flour, baking soda, baking powder, salt and cinnamon in a lg mixing bowl, and sir with a fork to mix everything well. Scoop out about 1/4 cup of the flour mixture and combine it in a small bowl with chopped walnuts and stirring and tossing to coat the nuts with the flour.
In a medium bowl combine the butter or oil, eggs, sugar chopped pears and vanilla and mixture the pears stir to mix everything well. Scrape the pear mixture into the flour mixture and stir just until flour disappears and the butter is evenly moistened.
Quickly scrape the batter into the prepared pans and bake at 350 for 60 to 70 mins or until the bread is browned and firm on top, and a tooth pic comes out clean.
Cool the bread in the pans on a wire rack about 10 mins. Then turn it out on to a plaate or wire rack to cool completely top side up. Serve as is or sprinkle with powdered sugar.