Making Double Chocolate Chip Cookies

Ingredients

• 1/2 cup unsalted softened butter
• 1/2 cup granulated sugar
• 1/2 cup packed light or dark brown sugar
• 1 large egg
• 1 teaspoon pure vanilla extract
• 1 cup all-purpose flour
• 2/3 cup unsweetened cocoa powder
• 1 teaspoon baking soda
• 1/8 teaspoon salt
• 1 Tablespoon milk
• 1 and 1/4 cups semi-sweet chocolate chips