Preheat your oven to 160 Degrees Celsius Fan-force (or 180 Degrees Celsius without fan) and line 2 baking trays with grease proof paper.
In a large bowl, add your softened butter, caster sugar and brown sugar. Using electric beaters, beat until light, fluffy and all the sugars are combined. Add in the vanilla extract and egg and beat again, until well incorporated.
Add in the peanut butter and beat again! You should have a smooth, luscious mixture at this point.
Pop your flour and baking powder in on top, again just throw it in unceremoniously, there's no need to sift here! Fold through gently until all the flour is mixed in, then add your chocolate chips and roughly chopped peanuts and combine.
Take a heaped teaspoons of the mixture and roll into balls, place onto your prepared trays and pop them straight into the oven. You don't need to give them more than a few centimeters distance as they don't spread much.
Check on your cookies at 8 minutes, they will be done when they start to turn golden brown on the outer edges and just lightly over the top. They'll still be soft to touch, so don't attempt to remove them from the tray just yet! If they're not quite ready give them a further 2 minutes.
Once done, remove from the oven and allow to cool for 5 minutes or so, until they are solid enough to move. Then transfer to a wire rack to cool completely.... you may or may not start eating them now, with a glass of cold milk of course!!
If you want to take your crunchy chocolatey cookies to the next level you can drizzle with the extra dark chocolate, peanut butter and sprinkle with sea salt. Honestly, they're amazing like this!!
Simply melt your peanut butter in 10 second bursts in the microwave until runny. Do the same to your dark chocolate chips in a separate bowl with the tip of a teaspoon worth of coconut oil if you wish to make it beautifully runny and smooth. Use a fork to drizzle over the cookies and finish with a light sprinkle of sea salt flakes!