Preheat oven to 160°C.
Beat together butter, sugars and vanilla with the stand mixer for 5 minutes or until pale and creamy. Scrape down the sides.
Add the eggs one at a time and beat well between each addition.
Place the flour and baking powder in a bowl and whisk together to ensure no lumps.
Add the flour and mix gradually on low speed until a dough forms.
Add the Chocolate baking chips and mix on low for about 30 seconds until combined.
Take half the dough (it will be a bit sticky at this stage) and roll into a log with baking paper. Then cover with cling wrap. Repeat with the remainder of the dough.
At this stage you can either place the logs of dough in the freezer to be used when you need it or you can refrigerate for 1hr.
When the dough is firm take it out of the refrigerator (or freezer) and slice into 1cm wide discs. Place on baking tray and cook for 18-20 minutes or until caramel in colour (it may take longer if baking from frozen, just keep checking every minute after 20 minutes as they will burn quickly). These cookies will spread during baking so make sure they are not too close together.
Leave cookies on try to cool.