Preheat the oven to 350 F. Grease and flour a 9x5-inch loaf pan.
In a medium-sized bowl, whisk together the oil and sugar until combined. Add the eggs, one at a time, and vanilla extract. Whisk until light and fluffy.
Stir in the mashed bananas and drained crushed pineapple
Stir in the flour, baking powder, baking soda, ground cinnamon, and salt, just until combined. Do not overmix.
Pour the batter into the prepared pan and bake for 60-70 minutes or until a toothpick inserted in the middle comes out clean.
Let the loaf cool down for 5 minutes in the pan, then transfer to a cooling rack to cool down completely.