Once the butter has cooled, add the sunflower oil, water, vanilla and egg and whisk until completely combined and the color has lightened, about 1 to 2 minutes. Add in the brown sugar, sugar, baking powder, baking soda and salt, whisking to combine, about 1 minute. Grab a spatula and fold in the flour until just combined and you still see small streaks of flour. Lastly, add in the chocolate chips and fold into the dough until evenly distributed. Lay a piece of piece of plastic wrap over the top of the dough and let the dough chill in the fridge for 20 minutes.