Preheat the oven to 180°C/375F. In a bowl, beat the butter until pale.
Add both sugars to the bowl.
Add the egg and a few drops of vanilla essence.
Add the baking powder and salt.
Add flour in two batches. There's no need to sift the flour.
Add the chocolate chips. Using a spoon, drop the dough onto a baking sheet (do not flatten out after dropping).
Bake in the oven for 8-10 minutes at 180-185°C (375F for American ovens.) If you like your cookies crispy, up to 15 minutes should be fine.
They should puff up like this after about 8 minutes. When removed from the oven, they will shrink and become nice and chewy with a soft texture.
Story Behind this Recipe
I wanted to make easy American-style cookies, so tried playing around with my Grandma's recipe.
The cookies may seem too soft when you take them out of the oven, but this is what makes them so delicious! If you find yourself thinking 'hm, these still seem a bit undercooked', that's when you should take them out – you'll see what I mean once they cool down (takes about 10 minutes).