Rustic Banana Bran Muffins

Name: Rustic Banana Bran Muffins
Ingredients: 1/2 cup boiling water; 2 cups bran cereal (not flakes--I used Nature's Path Organic Smart Bran), divided; 1/3 cup canola or other vegetable oil; 1 large egg; 3/4 cup all-purpose flour; 1/2 cup whole wheat flour; 1/3 cup granulated sugar; 1 teaspoon baking powder; 1 teaspoon baking soda; 1/2 teaspoon salt; 1 1/4 cups buttermilk; 1/4 cup dark or golden brown sugar; 3 tablespoons flaxseeds, ground (or a heaping 1/3 cup flax meal); 1 very ripe banana, cut into chunks