1. Preheat oven to 375°F. Place a cupcake liner in each cup of a 12-cup muffin pan; set aside. For the topping, place turbinado sugar, flour, cinnamon and butter in a food processor. Pulse and process until mixture resembles coarse crumbs; set topping aside.
2. For the batter, in a medium bowl combine flour, baking powder and salt; set aside. In a large bowl beat together butter and granulated sugar until creamy. Beat in egg; mix until well-blended. Add flour mixture alternately with buttermilk, mixing well after each addition. Gently fold in blueberries.
3. Spoon batter evenly into muffin cups; sprinkle with topping. Bake 35 to 38 minutes or until a toothpick inserted into the center of a muffin comes out clean. Let muffins cool in pan 5 minutes. Transfer to a cooling rack; let cool completely.

260 calories, 8g fat, 5g saturated fat, 35mg cholesterol, 135mg sodium, 44g carbohydrate, 1g fiber, 4g protein

*cooling time extra