Preheat oven to 400º and generously grease 12 muffin cups (1/2-cup capacity). Sift cornmeal, flour, granulated sugar, baking powder, baking soda, and salt into a medium bowl. In a separate bowl, whisk together buttermilk, eggs, and melted butter. Make a well in the center of the dry ingredients, pour liquid ingredients into well, and stir to combine. Fold in berries.
Fill each muffin cup 2/3 full with batter and sprinkle tops with pearl sugar if you like. Bake until golden on top, about 25 minutes. Transfer tin to a rack and let cool 10 minutes before removing muffins.