Preheat oven to 350F/175C. Butter (9 x 5 x 3 by inch) metal loaf pan, then dust with flour, knocking out excess. (my loaf pan is 13 inch long)
Sift together the flour, baking soda, cinnamon powder and salt into a bowl.
Beat together eggs and sugar in bowl of electric mixer at medium-high speed until very thick and pale and mixture forms a ribbon when beater is lifted, about 10 minutes. Reduce speed to low and add oil in a slow stream, mixing, then mix in bananas, yohurt and vanilla. Remove from mixer and fold in flour mixture and half of the chopped walnuts gently and thoroughly with a rubber spatula.
Pour the batter into the loaf pan, spreading evenly and sprinkle remaining chopped walnuts on top.
Bake in middle of oven until golden and a skewer comes out clean, 1 to 1¼ hours. (I only baked for 55 minutes).
Recipe by Anncoo Journal at https://www.anncoojournal.com/banana-walnut-bread/