The Best Bran Muffins

Ingredients

• 1 1/4 cups bleached all-purpose flour
• 1/4 cup whole-wheat flour
• 1 1/4 teaspoons baking powder
• 1/2 teaspoon baking soda
• 3/4 teaspoon table salt
• 1 1/4 teaspoons ground cinnamon
• 3/4 teaspoon ground allspice
• 1/2 teaspoon fresh grated nutmeg
• 7 tablespoons unsalted butter, softened
• 1/2 cup dark brown sugar plus 2 additional tablespoons
• 2 large eggs
• 2 1/2 teaspoons vanilla extract
• 3 tablespoons unsulphured molasses
• 1/4 cup sour cream
• 1 cup buttermilk plus 3 additional tablespoons
• 1 1/2 cups wheat bran
• 1 cup raisins