1Preheat oven to 400 degrees F (200 degrees C). Grease muffin cups or line with paper muffin liners.
2In a large bowl, combine flour, cornmeal, sugar, salt, baking powder and baking soda. In a separate bowl, beat together oil, vanilla and egg. Stir egg mixture into dry ingredients alternating with the buttermilk just until moistened. Gently fold in the blueberries. Spoon batter into prepared muffin tins.
3Bake in preheated oven for 20 to 25 minutes, until golden. Serve warm.