1 1/2 cups all-purpose flour
1 1/2 cups yellow cornmeal
3/4 cup sugar
2 teaspoon baking powder
1 teaspoon baking soda
1/2 teaspoon salt
2 large eggs, lightly beaten
3/4 cup well-shaken buttermilk
3/4 cup canola oil
1 teaspoon pure vanilla extract
1 1/2 cups fresh or frozen blackberries
Preheat the oven to 375 degrees F. Line 12 large muffin cups with liners and spray the top of the pan lightly with vegetable oil spray or grease lightly.
Stir the flour, cornmeal, sugar, baking powder, baking soda, and salt together in a large bowl.
In a separate large bowl, stir the eggs, buttermilk, oil, and vanilla together. Gradually add the flour-cornmeal mixture, stirring just until the dry ingredients are moist and no flour is visible. Do not mix more than necessary. Gently fold in the blackberries.
Scoop the batter with a 1/3-cup measure or ice cream scoop to fill the muffin tins to just below the top of the liner. Bake the muffins for 25 to 30 minutes, until the tops spring back when pressed lightly and a toothpick iserted into the center of a muffin comes out clean. Allow the muffins to cool in the pan for 5 minutes before turning them out.
Note: I used standard muffin tins and ended up with enough batter for 18 muffins.