Preheat an oven to 325 degrees F (165 degrees C). Line the bottom of two 9×5-inch loaf pans with parchment paper.
Mix flour, baking soda, salt, baking powder, and cinnamon in a bowl. Beat sugar, vegetable oil, eggs, and vanilla extract together in a large mixing bowl, and stir in zucchini and pineapple. Gradually pour in the flour mixture, mixing until just incorporated. Fold in raisins and walnuts, mixing to evenly combine. Divide batter evenly between the two prepared loaf pans.
Bake in the preheated oven until a toothpick inserted into the center comes out clean, about 1 hour. Working with one loaf at a time, hold the pan on its side and gently tap the sides of the pan against the counter to loosen it. Cover the pan with a cooling rack, and invert it to tip the cake out of the pan and onto the rack. Peel off the parchment paper, and allow bread to cool completely.