Luscious buttermilk is a tangy cultured milk product made by adding healthful bacteria to whole or low-fat milk. Its slightly thick, cream like consistency and gentle acidity make it an excellent tenderizer in muffins and quick breads. Recipes using buttermilk usually call for baking soda, an alkaline leavener that reacts with the acidity in buttermilk. The resulting carbon dioxide bubbles expand in the heat of the oven, creating steam that helps produce rounded, moist muffins.
Fresh blueberries are best for this recipe, but if you have only frozen berries, stir them into the batter without thawing, or their dark juice will turn the muffins purple.
Blueberry Buttermilk Muffins with Cinnamon Streusel (Makes 18 muffins)
For the topping:
1/4 cup all-purpose flour
2 tablespoons each granulate sugar and firmly packed light brown sugar
1/4 teaspoon ground cinnamon
2 tablespoons cold, unsalted butter, cut into small pieces
For the muffins:
7 tablespoons unsalted butter, at room temperature
3/4 cup granulated sugar
2 large eggs
2 1/4 cups all-purpose flour
4 teaspoons baking powder
1 teaspoon baking soda
1/2 teaspoon salt
1 cup buttermilk
1 1/2 teaspoons vanilla extract
1 1/2 cups fresh blueberries or frozen unsweetened blueberries, unthawed
Preheat the oven to 375 degrees F. Grease two 12 standard muffin cups with butter or line with paper muffin liners.
To make the topping, stir together the flour, granulated sugar, brown sugar, and cinnamon in a small bowl. Using a pastry cutter or your fingers, cut or rub the butter into the dry ingredients just until coarse crumbs form. Alternatively, combine the dry ingredients and the butter in a food processor and pulse just until coarse crumbs form.
To make the muffins, in a bowl, using an electric mixer on medium speed, cream together the butter and sugar until light and fluffy. Add the eggs, one at a time, beating well after each addition until blended into the butter mixture.
In another bowl, stir together the flour, baking powder, baking soda, and salt. Add the dry ingredients to the butter mixture in 2 increments, alternating with the milk and vanilla. Stir just until evenly moistened. The batter will be slightly lumpy. Using a large rubber spatula, gently fold in the blueberries just until evenly distributed, no more than a few strokes. Take care not to break up the fruit. Do not overmix.
Spoon the batter into each muffin cup, filling it level with the rim of the cup. Sprinkle each muffin with some topping.
Bake until golden, dry, and springy to the touch, 20-25 minutes. A toothpick inserted into the center of a muffin should come out clean. Transfer the pan to a wire rack and let cool for 5 minutes. Unmold the muffins. Serve warm or at room temperature.
Preheat the oven to 375 degrees F. Grease two 12 standard muffin cups with butter or line with paper muffin liners.
To make the topping, stir together the flour, granulated sugar, brown sugar, and cinnamon in a small bowl. Using a pastry cutter or your fingers, cut or rub the butter into the dry ingredients just until coarse crumbs form. Alternatively, combine the dry ingredients and the butter in a food processor and pulse just until coarse crumbs form.
To make the muffins, in a bowl, using an electric mixer on medium speed, cream together the butter and sugar until light and fluffy. Add the eggs, one at a time, beating well after each addition until blended into the butter mixture.
In another bowl, stir together the flour, baking powder, baking soda, and salt. Add the dry ingredients to the butter mixture in 2 increments, alternating with the milk and vanilla. Stir just until evenly moistened. The batter will be slightly lumpy. Using a large rubber spatula, gently fold in the blueberries just until evenly distributed, no more than a few strokes. Take care not to break up the fruit. Do not overmix.
Spoon the batter into each muffin cup, filling it level with the rim of the cup. Sprinkle each muffin with some topping.
Bake until golden, dry, and springy to the touch, 20-25 minutes. A toothpick inserted into the center of a muffin should come out clean. Transfer the pan to a wire rack and let cool for 5 minutes. Unmold the muffins. Serve warm or at room temperature.
