Preheat oven to 425 degrees F. Rub 12 muffin cups with butter or shortening.
Mix the dry ingredients (cornmeal through salt) in a mixing bowl. In a second bowl or in a large glass measure, whisk together the egg, milk, oil, and vanilla.
Pour the egg mixture into the dry mixture and stir just until blended. Stir in the blueberries.
Divide the batter equally among the muffins cups (it will come almost to the top) and bake on center rack for 16-18 minutes or until the muffins appear golden brown around the edges.
