1. Preheat oven to 350 Degrees. 2. Spread a single layer of walnuts onto a baking sheet and toast walnuts in the preheated oven for 8-10 minutes. (WATCH CAREFULLY BECAUSE THEY CAN QUICKLY BURN!) Remove from the oven and let cool 3. Using a whisk, mix flour baking powder, baking soda and salt in a mixing bowl. 4. in a separate bowl mix together sugar. lemon zest, buttermilk, eggs, vanilla, melted butter and oil. 5. Pour liquid ingredients into a pit created in the bowl of dry ingredients and lightly combine. (Take care not to overmix.) Dust blueberries and chopped walnuts with flour and then fold them into the batter. 6. Grease and flour an 8" x 4" loaf pan. Spread mixture into the pan. 7. Bake for 55 to 60 minutes or until toothpick inserted in the center comes out clean. When finished baking, allow to cool for about 20 minutes before removing from the pan. 8. GLAZE: mix the powdered sugar and lemon juice and stir well. 9. Brush or drizzle onto loaf while it's still warm. 10. Wait for compliments to roll in! :-)