Heat Oven to 350°.  Grease bottom only of 8-inch square pan.

Melt in 2-quart saucepan over low heat, stirring constantly:

  ¼  cup  Margarine or butter  [½ stick]
 1  pkg  Semisweet Chocolate chips  [6 ounces]
 

Beat in thoroughly with spoon:

 ¾  cup  All-purpose flour
 ½  tsp  Vanilla
 ½  cup  Sugar
 ¼  tsp  Baking powder
 1/3 cup  Walnuts  [crushed]
 ¼  tsp  Salt
 1/3 cup  Mashed ripe Banana  [about 1 small]
 
 

Spread batter evenly in pan.

Bake about 30 minutes or until center is set; cool completely.

Cut into 2-inch squares.