Preheat oven to 375°F (190°C). Line a muffin tin with paper liners.
In a large bowl, mix flour, sugar, baking powder, and salt.
In another bowl, whisk together milk, oil, eggs, and vanilla extract.
Pour the wet ingredients into the dry ingredients and stir until just combined.
Gently fold in the wild blackberries.
Divide the batter evenly among the muffin cups.
Bake for 20 minutes or until a toothpick inserted into the center comes out clean.
Let cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.