Step 1: In a large mixing bowl, thoroughly whisk together the all-purpose flour, unsweetened cocoa powder, granulated sugar, baking powder, and salt until well combined.
Step 2: In a separate medium bowl, whisk together the milk, the large egg, the 2 tablespoons of melted unsalted butter, and the vanilla extract until the mixture is smooth.
Step 3: Pour the wet ingredients into the bowl with the dry ingredients. Stir gently using a whisk or rubber spatula just until the ingredients are moistened. Do not overmix; a few lumps are normal. If using, gently fold in the chocolate chips.
Step 4: Heat a non-stick skillet or griddle over medium heat. Lightly grease with a small amount of butter or cooking spray. Pour about 1/4 cup of batter per pancake onto the hot surface. Cook for 2-3 minutes, or until bubbles form and begin to pop on the surface.
Step 5: Carefully flip each pancake with a spatula and cook for another 1-2 minutes, or until the second side is golden brown and the pancake is cooked through. Repeat with the remaining batter, adding more butter as needed.
Step 6: Serve the warm chocolate pancakes immediately with your favorite toppings such as maple syrup, whipped cream, fresh berries, or a dusting of powdered sugar. Enjoy your decadent breakfast!