1Heat oven to 400°F. Grease bottoms only of 12 regular-size muffin cups or line with paper baking cups. In small bowl, mix 1/4 cup brown sugar and 1/4 cup pecans. Cut in butter, using pastry blender (or pulling 2 table knives through ingredients in opposite directions), until crumbly. Set aside.
2In large bowl, beat 1/2 cup brown sugar, the milk, oil, vanilla and egg until well blended. Stir in flour, baking powder and salt just until ingredients are moistened. Fold in peaches and 1/2 cup pecans. Divide batter evenly among muffin cups (cups will be almost full). Sprinkle with topping.
3Bake 18 to 20 minutes or until golden brown. Immediately remove from pan to cooling rack.