Ingredients

• 1/2 cup all-purpose flour
  
• 1 cup quick-cooking rolled oats
  
• 1/2 cup packed brown sugar
  
• 1/4 teaspoon baking soda
  
• 1/2 cup butter, melted
  
• 1 egg
  
• 3/4 cup granulated sugar
  
• 2/3 cup all-purpose flour
  
• 1/4 cup milk
  
• 1/4 cup butter, melted
  
• 1 ounce unsweetened chocolate, melted and cooled
  
• 1 teaspoon vanilla
  
• 1/4 teaspoon baking powder
  
• 1/2 cup chopped walnuts
  
• 1 ounce unsweetened chocolate
  
• 2 tablespoons butter
  
• 1 1/2 cups sifted powdered sugar
  
• 1/2 teaspoon vanilla
  
• Walnut halves (optional)