Ideally using a stand mixer with the paddle attachment, mix the butter, caster sugar and light brown soft sugar together until fluffy and paler in colour. This will take 3-5 minutes in an electric mixer (I use speed 3)
Add the egg and vanilla extract and mix in
Add the plain flour, cocoa powder, baking powder, bicarbonate of soda and salt (you can mix them together in a separate bowl first if you like) and mix them in until just combined
Then mix in the milk chocolate chips and Pringles briefly, just to evenly distribute them. If you are not using a stand mixer, I recommend crushing up the Pringles first
Divide the dough into portions, I weighed the dough out to make each cookie an equal size. Roll the dough portions into balls using your hands, place them on either a lined baking tray, or into a tupperware container lined with baking paper. Chill them in the fridge for 30 minutes
Meanwhile, pre-heat your oven to 180C Fan/400F/Gas Mark 6. After the 30 minutes is up and your oven is pre-heated, place the dough balls onto lined baking trays, leaving space (at least 2") between them to spread. If you don't have enough baking trays, keep the dough in the fridge and bake the cookies in batches
Bake the cookies for 12-14 minutes, remove from the oven and leave to cool on the trays for at least 10 minutes before moving to a cooling rack
Store leftovers in an airtight container and eat within 3 days
Notes
Make sure all your ingredients (particularly the butter and egg) are at room temperature before you start baking.
I prefer to use unsalted butter for this recipe, but you can also use a baking spread. Baking spreads do contain more water, so your cookie dough could be looser.
I recommend using light brown soft sugar for delicious flavour and a more gooey cookie, but you can replace it with caster sugar if you can't get hold of light brown soft sugar.
I used milk chocolate chips in the cookies, you could use dark or white chocolate, or a combination!
You can use any cocoa powder for this recipe, of course the better quality it is, the better flavour it will have. Also do make sure you are using cocoa powder and not a hot chocolate powder.
I used ready salted original flavour Pringles for this recipe. You can also use any ready salted crisps, however if they are quite salty you may want to reduce or omit the salt in the cookie dough.
Although I provide cup measurements, I highly recommend weighing your ingredients out using digital kitchen scales. It is the most accurate way to measure ingredients and will ensure the best results. Digital scales are very low cost and can be purchased for around £12 ($16.50).
For teaspoon (tsp) and tablespoon (tbsp) measurements, please use measuring spoons and not the type of spoons you eat with. Again this will ensure accuracy and provide the best results.