2 teaspoons finely grated zest from 1 lemonMuffins:
2 cups (about 10 ounces) blueberries, fresh or frozen
1 cup plus 1 tablespoon sugar
2 1/2 cups (12½ ounces) flour
2 1/2 teaspoons baking powder
1 teaspoon salt
2 large eggs
4 tablespoons unsalted butter room temperature
¼ cup vegetable oil
1 cup buttermilk
1 teaspoon vanilla extract
Ingredients
FOR TOPPING: Stir together sugar and lemon zest in small bowl until combined; set aside.
FOR MUFFINS: Adjust oven rack to upper-middle position and heat oven to 425 degrees. Spray standard muffin tin with nonstick cooking spray. Bring 1 cup blueberries and 1 teaspoon sugar to simmer in small saucepan over medium heat. Cook, mashing berries with spoon several times and stirring frequently, until berries have broken down and mixture is thickened and reduced to ¼ cup, about 6 minutes. Transfer to small bowl and cool to room temperature, 10 to 15 minutes.
Whisk flour, baking powder, and salt together in large bowl. Whisk remaining 1 1/8 cups sugar and eggs together in medium bowl until combined, about 45 seconds. Slowly whisk in butter and oil until combined. Whisk in buttermilk and vanilla until combined. Using rubber spatula, fold egg mixture and remaining cup blueberries into flour mixture until just moistened. (Batter will be very lumpy with few spots of dry flour; do not over mix.)
Use ice cream scoop or large spoon to divide batter equally among prepared muffin cups, batter should completely fill cups and mound slightly. Spoon teaspoon of cooked berry mixture into center of each mound of batter. Using small spoon, gently swirl berry filling into batter. Sprinkle lemon sugar evenly over muffins.
Bake until muffin tops are golden and just firm, 17 to 19 minutes, rotating muffin tin from front to back halfway through baking time. Cool muffins in muffin tin for 5 minutes, then transfer to wire rack and cool 5 minutes before serving.
Notes
-*If buttermilk is unavailable, substitute 3/4 cup plain whole-milk or plain yogurt thinned with 1/4 cup milk. Also, I have experimented with 3/4 cup buttermilk and like the results, the batter holds the blueberry topping better so it doesn't cause the muffin top to collapse quite as much!-I mixed all of the dry ingredients in a bowl, then mixed the wet ingredients together, and folded the dry into the wet ingredients. Then folded in the blueberries.-Best when eaten warm or with in 12 hours of baking. -This recipe makes 12 large beautifully shaped muffins.