Double Chocolate Brownies

Ingredients (10)

• 1/2 cup all-purpose flour
• 1/3 cup unsweetened cocoa powder
• 1/4 teaspoon salt
• 1/4 teaspoon baking powder
• 1 cup good quality semisweet chocolate chips
• 1 stick of butter
• 1 cup white sugar
• 2 eggs
• 1 teaspoon pure vanilla extract
• handful of roughly chopped walnuts