1. Heat oven to 375-F. Grease twelve 3-inch muffin-pan cups. In large bowl, combine flour, sugar, baking powder, baking soda, and salt; add cloves, if desired. Add blueberries and toss to coat with flour mixture; set aside. 2. In medium-size microwave-safe howl, microwave butter on medium (50 percent), 10 to 15 seconds, or until melted. Cool slightly, then add yogurt, egg, lemon rind, and lemon and vanilla extracts; beat until blended. 3. Stir yogurt mixture into flour-berry mixture just until blended and dry ingredients are moisteneddo not overmix. Divide batter among muffin-pan cups. Bake 20 to 25 minutes or until muffins spring back when gently pressed with fingertip. Cool in pan on wire rack 5 minutes. Remove muffins from cups and serve warm. Nutrition information per muffinprotein: 4 grams; fat: 4 grams; carbohydrate 32 grams; fiber: 1 gram; sodium 238 milligrams; cholesterol: 26 milligrams; calories: 161.