Triple Chocolate Brownies

Bahan-bahan (24 porsi)

• 3 ounces unsweetened chocolate, (coarsely chopped)
• 2 ounces semi-sweet chocolate, (coarsely chopped)
• ½ cup (1 stick) butter
• 1 cup all purpose flour
• ½ teaspoon salt
• ¼ teaspoon baking powder
• 1½ cups granulated white sugar
• 3 large eggs
• 1 teaspoon vanilla extract
• ¼ cup sour cream
• ½ cup milk chocolate chips
• 3 tablespoons powdered sugar