Sourdough Blueberry Muffins

 This recipe comes from SugarSpunRun.com, with my modifications. As usual, I've reduced the sugar and oil from the original recipe.

Ingredients

1 ½ cups (187 g) all-purpose flour (I used 1/2 cup whole wheat flour and 1 cup white flour)
½ cup (100 g) granulated sugar (recipe called for 1 cup...too sweet!)
2 teaspoons baking powder
½ teaspoon baking soda
½ teaspoon table salt
½ cup (113 g) unsalted butter melted (I used 1/3 cup vegetable oil)
½ cup (105 g) sourdough discard
¾ cup (180 g) sour cream or plain full-fat Greek yogurt (I used vanilla yogurt)
1 large egg room temperature preferred
1 teaspoon vanilla extract
1 ½ cups (210 g) fresh blueberries (I used frozen)
Granulated sugar for topping optional

Directions

1. Preheat oven to 425F (220C) and line a 12-count muffin tin with paper liners. Set aside.
2. In a large mixing bowl, whisk together flour, sugar, baking powder, baking soda, and salt.
3. In a separate mixing bowl, whisk together melted butter, sourdough discard, sour cream, egg, and vanilla extract until ingredients are evenly mixed.
4. Add wet ingredients to dry and use a spatula to gently fold together. Once batter is about 50% combined, add blueberries and continue to mix, gently, until blueberries are well-distributed and batter is just combined. Do not over-mix or muffins will be dense and dry.
5. Evenly divide batter into prepared muffin tin. If desired, sprinkle with granulated sugar.
6. Transfer to center rack of 425F (220C) oven and bake for 8 minutes, then, without opening the oven door, decrease oven temperature to 350F (175C) and bake for 12 minutes longer/until muffins are baked through. The tops will be beginning to turn a light golden brown and a toothpick inserted in the center should come out clean or with moist crumbs.
7. Allow muffins to cool for 10 minutes in the muffin tin before carefully removing to a cooling rack to cool completely.