01 - Preheat oven to 350°F (180°C). Line a baking sheet with parchment paper and set aside.
02 - In a large mixing bowl, cream together the softened butter, granulated sugar, and packed brown sugar using an electric mixer until the mixture is light and fluffy, approximately 2–3 minutes.
03 - Beat in the egg and vanilla extract until fully combined and the mixture is smooth.
04 - In a separate bowl, whisk together the all-purpose flour, baking soda, and salt. Gradually add the dry mixture to the wet ingredients, mixing until just combined. Avoid overmixing.
05 - Divide the dough into 16 equal portions. Flatten each portion in the palm of your hand, place one piece of chocolate in the center, and fold the dough around it. Gently roll between your palms to seal and form a smooth ball.
06 - Place the filled cookie balls on the prepared baking sheet, spacing them approximately 2 inches apart to allow for spreading.
07 - Bake for 10–12 minutes, until the edges are lightly golden but the centers still appear soft and slightly underdone.
08 - Allow the cookies to rest on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.