First of all, preheat your oven to 180°C (or 160°C fan).
Cream together the butter and sugars until fluffy.
Add the eggs, one at a time, beating well after each addition. Followed by Vanilla.
Separately mix together the flour, salt and baking powder before mixing it in slowly on a low speed. (At this point I noticed that my cookie dough was a tad too sticky so I added a bit more flour until it firmed up a little.)
Fold in the chocolate chips.
Now comes the fun bit.
Recipe by The Bearded Bakery at http://www.thebeardedbakery.com/baking/cookies/reeses-cup-cookies/