Preheat your oven to 180°C (350°F) and line a baking sheet with parchment paper.
In a large mixing bowl, combine the peanut butter and dark brown sugar. Use a spatula or spoon to stir until the mixture is smooth, slightly fluffy, and fragrant with a warm nutty aroma.
Add the egg and vanilla extract to the bowl. Whisk or stir until the mixture becomes glossy and well incorporated, about 1-2 minutes.
Sprinkle the baking soda over the mixture and gently fold in the all-purpose flour. Mix just until combined; the dough will be soft and slightly sticky but manageable.
Gently fold in the chocolate chips, distributing them evenly throughout the dough. You should see specks of melty chocolate in the dough.
Using a cookie scoop or spoon, portion out about 2 tablespoons of dough for each cookie and place them on the prepared baking sheet, spacing them about 2 inches apart. Press a few extra chips on top for a decorative touch.
Bake in the preheated oven for 10-12 minutes, until the edges are golden brown and slightly crisp, while the centers remain soft and gooey.
Remove the cookies from the oven and let them rest on the baking sheet for about 5 minutes—they will firm up slightly and make handling easier.
Transfer the cookies to a wire rack to cool completely, allowing the chocolate to set just enough for perfect bite-sized gooeyness.
Once cooled, enjoy these soft, chewy cookies with a glass of milk or your favorite beverage—perfect for satisfying nostalgic cravings.