Preheat your oven to 180°C (350°F) and line a baking sheet with parchment paper to prevent sticking.
In a large bowl, combine softened butter, brown sugar, and peanut butter. Use an electric mixer or a sturdy spoon to beat until the mixture is smooth, creamy, and slightly fluffy, and the color lightens.
Add the egg and vanilla extract to the bowl, then mix well until fully incorporated and the mixture is glossy.
In a separate bowl, whisk together the flour, baking soda, and salt to evenly distribute the leavening agents.
Gradually add the dry ingredients to the wet mixture, mixing gently just until the flour is combined and the dough is thick and slightly sticky.
Fold in the chocolate chips, distributing them evenly throughout the dough, which will look chunky and speckled with chocolate.
Scoop spoonfuls of dough onto the prepared baking sheet, spacing them about 2 inches apart to allow for spreading.
Bake in the preheated oven for 10-12 minutes, watching for the edges to turn golden brown and the centers to look just set and slightly puffy.
Remove the cookies from the oven and let them rest on the baking sheet for about 5 minutes; they will firm up slightly as they cool.
Use a spatula to transfer the cookies to a cooling rack, allowing them to cool completely and develop their chewy, golden exterior with melty chocolate pockets.
Once cooled, enjoy these rustic, messy cookies with a glass of milk or share them straight from the rack—each batch is uniquely charming and comforting.