Preheat oven to 400 F. Line 30 mini-muffin pan cups or 12 medium muffin cups with paper liners, or spray bottoms only wtih cooking spray. In medium bowl, combine flour, wheat germ, brown sugar, baking powder and salt; mix well. In small bowl, combine apple butter, milk, margarine and egg whites until well blended. Add to flour mixture, stirring just until dry ingredients are moistened. Fill muffin cups almost full with batter. Prepare streusel topping (see below); sprinkle evenly over batter, patting gently. Bake mini-muffins 12 to 15 minutes, and larger muffins 20 to 22 minutes, or until wooden toothpick inserted in center comes out clean. Serve warm. STREUSEL TOPPING: in small bowl, combine all ingredients; mix until well blended. Notes: To freeze, wrap muffins securely in foil or place in freezer bag. Seal, label and freeze. To reheat muffins, unwrap; microwave on High (100% power) about 30 seconds per muffin. Per Serving (1 mini-muffin): About 75 cal, 5 g pro, 13 g car, 2 g fat, 24% cal from fat, 0 mg chol, 65 mg sod.