Preheat oven to 400 degrees F. Line a standard muffin pan with 12 muffin liners or grease the pan well.
Whisk together egg, egg white, buttermilk, oil, vanilla extract, and coconut extract in a medium bowl.
1 large egg, 1 large egg white, 1 cup buttermilk, 2 tablespoons vegetable oil, 1 teaspoon vanilla extract, ½ teaspoon coconut extract
In a separate large bowl, whisk together sugar, flour, baking powder, baking soda, and salt.
¾ cup granulated sugar, 2 ¼ cups all purpose flour, 1 ½ teaspoons baking powder, ½ teaspoon baking soda, ¾ teaspoons kosher salt
Pour wet ingredients into the dry ingredients. Mix until just combined. The batter will be thick.
Fold in coconut flakes.
½ cup sweetened coconut flakes
Spoon batter into prepared muffin pan until each cup is ⅔ full. Sprinkle some additional coconut flakes over top.
Bake for 15-20 minutes or until a toothpick inserted in the middle comes out clean.
Notes
Buttermilk: I recommend using whole milk buttermilk because there isn't a lot of oil in this recipe. Using buttermilk with more fat in it will give you softer muffins. You can make your own buttermilk substitute.
Vegetable oil: Or a similar neutral oil.
Coconut flavor: If you'd like stronger coconut flavor, you can use all coconut flavor in place of the vanilla or use 1 teaspoon of coconut flavor and 1/2 teaspoon of vanilla.
Flour: It’s important to properly measure the flour to avoid dry, heavy muffins. Weighing the flour is the most accurate method of measuring it. You can also sift or stir the flour to break it up and then lightly spoon it into the measuring cup and level. Avoid packing the flour.