Preheat the oven to 425 degrees F and line a muffin pan with 6 parchment liners in every other cup.
In a small bowl, toss the blueberries with 15g (2 tbsp) flour to coat. Set aside.
In a separate small bowl, whisk together the flour, baking powder, and salt. Set aside.
In a large mixing bowl, beat the butter and sugar for 2-3 minutes until light and fluffy.
Scrape down the bowl, then add in the oil, egg, and vanilla, and mix until fully combined.
Add in half of the dry ingredients, mixing until just combined. Then, mix in the buttermilk, followed by the remaining dry ingredients.
Lastly, gently fold in the blueberries until evenly distributed.
Divide the batter up between 6 muffin cups. Top each muffin with a few extra blueberries and generously sprinkle with turbinado sugar.
Bake the muffins for 5 minutes, then turn the oven down to 375 degrees F and bake for another 15-18 minutes or until deeply golden and a toothpick inserted comes out clean.
Allow muffins to cool for a few minutes in the pan. Enjoy warm!