These muffins are what blueberry muffins should be - buttery, moist, studded with delicious blueberries. Oh, and the streusel topping definitely doesn't hurt either.
Blueberry Streusel Muffins (adapted from Cook’s Country)
1 1/4 cups all-purpose flour
1/3 cup packed dark brown sugar
1/3 cup granulated sugar
1/2 teaspoon ground cinnamon
7 tablespoons unsalted butter, melted
4 Tablespoons unsalted butter , melted and cooled slightly
2 cups all-purpose flour (I used 1 cup all-purpose and 1 cup white whole wheat and no one was the wiser)
1 large egg
1 teaspoon vanilla extract
1 cup granulated sugar
1 teaspoon grated lemon zest
1/2 cup buttermilk*
1 tablespoon baking powder
1/2 teaspoon salt
1 1/2 cups frozen blueberries
1. For the streusel: Combine flour, sugars, cinnamon, and salt in bowl. Drizzle with melted butter and toss with fork until evenly moistened and mixture forms large chunks with some pea-sized pieces throughout.
2. For the muffins: Adjust oven rack to middle position and heat oven to 375 degrees. Spray 12-cup muffin tin. Whisk egg in medium bowl until pale and evenly combined, about 30 seconds. Add vanilla, sugar, and zest and whisk vigorously until thick, about 30 seconds. Slowly whisk in melted butter; add buttermilk and whisk until combined.
3. Reserve 1 tablespoon flour. Whisk remaining flour, baking powder, and salt in large bowl. Fold in egg mixture until nearly combined. Toss blueberries with reserved flour and fold into batter until just combined.
4. Divide batter in muffin tin and top with streusel. Bake until light golden brown and toothpick inserted into center of muffin comes out with few dry crumbs attached, 23 to 27 minutes. Cool muffins in tin for 20 minutes, then carefully transfer muffins to rack to cool completely.
*If you don’t have buttermilk you can substitute 1 cup milk with 1 Tablespoon lemon juice. Just let it sit for about 10 minutes then use ½ cup for the muffins. Also, I’ve done this with soy milk and it works fine too.