Double Chocolate Skillet Cookie

Bahan-bahan (10 porsi)

• 3/4 cup (1½ sticks) unsalted butter, softened
• 1½ cups (packed) light brown sugar
• 2 large eggs
• 1½ teaspoons vanilla extract
• 1 teaspoon baking soda
• ¾ teaspoon salt
• 2 cups all-purpose flour (spooned into measuring cup and leveled-off)
• ¼ cup Dutch-process cocoa powder, (sifted)
• 1½ cups semi-sweet chocolate chips