PREHEAT oven to 350º F. Grease or paper-line 12 muffin cups.
COMBINE flour, granulated sugar, brown sugar, baking powder and salt in large bowl. Stir in butter, milk and egg just until moistened. Stir in morsels. Spoon batter into prepared muffin cups.
COMBINE brown sugar, flour and butter in small bowl; stir in nuts. Sprinkle generously over muffin batter; press down lightly.
BAKE for 20 to 25 minutes or until wooden pick inserted in center comes out clean.