Preheat your oven to 350°F (175°C) and grease a muffin tin or line it with cupcake liners.
In a large mixing bowl, combine the creamy peanut butter, brown sugar, and granulated sugar. Beat together until smooth and creamy.
Add the egg and vanilla extract to the peanut butter mixture, and mix until fully incorporated.
In a separate bowl, whisk together the baking soda and salt. Gradually add this dry mixture to the wet ingredients, stirring until just combined.
Fold in the chocolate chips until evenly distributed throughout the cookie dough.
Using a cookie scoop or spoon, fill each muffin cup with the dough, about 2/3 full.
Bake in the preheated oven for about 10-12 minutes, or until the edges are golden brown. The centers might look slightly underbaked, which is perfect for a soft cookie texture.
Allow the cookie cups to cool in the pan for about 5 minutes before transferring them to a wire rack to cool completely.
For an extra touch, sprinkle crushed peanuts on top of the cookie cups while they are still warm, allowing them to stick.
Notes
Serve warm or at room temperature, and drizzle with melted chocolate for a special touch.