Preheat oven to 375°F (190°C). Line or grease a 12-cup muffin tin.

In a large bowl, whisk together flour, sugar, baking powder, baking soda, and salt.

In another bowl, stir together pineapple (with juice), oil, egg, and vanilla.

Combine wet and dry ingredients. Stir until just mixed.

Spoon batter into muffin cups, filling each about 2/3 full.

Bake for 18–20 minutes, or until a toothpick comes out clean.

Cool for 5 minutes in pan, then transfer to a wire rack.

Serve warm or chilled. Enjoy!