Topping
1/4 cup packed brown sugar
1/4 cup chopped pecans
1 tablespoon firm butter or margarine

Mix with fork until crumbly. Set aside.

Muffins
1/2 cup packed brown sugar
1/2 cup milk
1/3 cup vegetable oil
1 teaspoon vanilla extract
1 egg
1 2/3 cups all-purpose flour
2 teaspoons baking powder
1/4 teaspoon salt
1 cup chopped fresh, frozen (thawed and
    drained) or canned (well drained) peaches
1/2 cup chopped pecans

Preheat oven to 400 degrees F. Grease bottoms only of 12 medium muffin cups or line with paper baking cups.

Beat brown sugar, milk, vegetable oil, vanilla extract and egg in a large bowl. Stir in flour, baking powder and salt just until moistened. Fold in peaches and pecans. Divide batter evenly among muffin cups (cups will be almost full). Sprinkle with reserved topping mixture. Bake for 18 to 20 minutes or until golden brown. Immediately remove from pan.