Pre-heat your oven to 160C Fan/350F/Gas Mark 4, grease a 26cm skillet pan with butter
Using a stand mixer with the paddle attachment, mix the butter and both sugars together until fluffy and paler in colour. This will take about 3 minutes
Add the egg and vanilla extract and mix in
Add the plain flour, baking powder and salt and mix them in, ony mix until just combined, be careful not to over mix
Add the chocolate chips and mix briefly, just to evenly distribute them
Using your hands, press the dough into the skillet pan until level
Bake for 25-30 minutes until lightly golden all over
Cool for 10 minutes (just so you don't burn your mouth!) then serve immediately
Once fully cool, you can cover it or transfer it to an airtight container, and store it at room temperature for 3 days
Video
Notes
Make sure your butter and egg are at room temperature before you start baking.
I highly recommend using light brown soft sugar, as it gives the skillet cookie wonderful flavour. If you can't get hold of it, you can use regular caster sugar, or even golden caster sugar would be good.
This skillet cookie is best made with plain flour (all purpose flour) and the added raising agents mentioned in the recipe. I wouldn't advise using self raising flour.
I used milk chocolate chips for this recipe, but you can use dark or white, or even a combination of two or three types.
If you don't have any chocolate chips, you can chop up a bar of chocolate instead.
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.