Preheat your oven to 400°F (200°C). Line a muffin tin with paper liners to prevent sticking.
In a large mixing bowl, whisk together the flour, sugar, baking powder, and salt until evenly combined.
In a separate measuring jug, whisk together the oil, egg, vanilla extract, and milk until smooth.
Pour the wet ingredients into the dry ingredients and stir gently until just combined (a few lumps are okay). Be careful not to over mix (the batter will be thick).
Gently fold in the blueberries, distributing them evenly throughout the batter.
Divide the batter between 8-9 muffin cups, filling each to the top for bakery-style muffins with oversized tops.
Bake for 15-20 minutes or until the tops are golden and a toothpick inserted into the center comes out with crumbs, not wet batter. Transfer the muffins to a cooling rack and let them sit for at least 10 minutes.