Preheat oven to 425°F. Line 12 standard muffin cups with paper liners or spray with nonstick cooking spray.
In a large bowl, add the lemon zest, granulated sugar and brown sugar. Mix the ingredients together with your fingertips until the sugar is moistened and fragrant.
2 teaspoons lemon zest, ½ cup granulated sugar, ¼ cup light brown sugar
To the sugar mixture, add the flour, baking soda and salt. In another bowl, combine the egg, lemon juice, buttermilk and oil. Create a small well in the dry ingredients, pouring the wet ingredients into the well and stirring just to combine. Gently fold in the blueberries.
2 ¼ cups all-purpose flour, ¾ teaspoon baking soda, ¼ teaspoon fine sea salt, 1 large egg, ¼ cup fresh lemon juice, ¾ cup buttermilk, 6 tablespoons vegetable oil, 6 ounces fresh blueberries
Divide batter evenly into the prepared muffin wells. The wells will be very full. Sprinkle the tops with coarse sugar.
Coarse sugar for topping
Bake at 425°F for 10 minutes. Leaving the oven door closed, set the oven temperature to 350°F and continue to bake for another 7-9 minutes, until the tops are golden and a toothpick inserted into the center comes out clean.
Let muffins cool in the pan for about 5 minutes before removing them to a wire rack to finish cooling.
Notes
Ingredients
If using frozen blueberries, do not thaw them before adding them to the batter.
You may substitute the vegetable oil for any neutral-flavored oil, such as avocado oil.
For a vegan version, substitute the buttermilk as noted above and swap the egg for a flax egg (1 tablespoon ground flax + 3 tablespoons water; allow to thicken for 5 minutes).
My favorite coarse sugar for topping muffins and quick breads is Sugar in the Raw Turbinado Cane Sugar.
Storage
Store muffins in an airtight container at room temperature for up to 3 days or freeze for up to 1 month.
Frozen muffins can be microwaved for 30-60 seconds to thaw and warm them through.