1. Preheat oven to 375ºF and grease or line a muffin tin.
2. In a medium bowl, whisk together the flour, baking powder, baking soda, salt, and sugar.
3. In a separate bowl, mix together the oil, egg, and buttermilk.
4. Add the wet ingredients to the dry ingredients and stir until just combined.
5. Gently fold in the blueberries.
6. Divide the batter among the muffin tin cups.
7. Bake for 18-22 minutes, or until a toothpick inserted into a muffin comes out clean.
8. Allow muffins to cool for 10 minutes before serving. Enjoy!