Prep: Preheat your oven to 350°F (175°C) and grease your 9x5-inch loaf pan.
Combine Dry: In a large bowl, whisk together the flour, sugar, baking powder, baking soda, salt, and cinnamon.
Combine Wet: In a separate bowl, whisk together the undrained crushed pineapple, eggs, vegetable oil, and vanilla extract.
Fold: Make a well in the center of the dry ingredients and pour in the wet mixture. Fold together with your spatula just until the flour is incorporated. Fold in the nuts. Do not overmix!
Bake: Pour the batter into your prepared pan. Bake for 55–65 minutes, or until a toothpick inserted into the center comes out clean.
Cool: Let the loaf cool in the pan for 10 minutes, then move to a wire rack to cool completely before slicing.