Heat oven to 400°F Place paper baking cup in each of 12 regular-size muffin cups, or grease bottom of each muffin cup with shortening. Place cereal in resealable food-storage plastic bag; seal bag and crush with rolling pin or meat mallet (or crush in food processor).
In medium bowl, stir together egg whites, oil and yogurt. Add cereal, flour, brown sugar, baking soda and salt; stir just until dry ingredients are moistened. Gently stir in berries. Divide batter evenly among muffin cups, filling each 3/4 full.
Bake 18 to 20 minutes or until golden brown. Immediately remove from pan.