Line a large baking sheet with parchment paper, set aside..
In a large mixing bowl, using a mixer, cream the butter and sugars together until fluffy for 2-3 minutes.
Add egg and vanilla and mix until combined.
Add the flour, baking powder, and salt. Mix together for a minute or so, dough will be crumbly.
Add in the chocolate chips and mix into dough. I like to use my hands to mix the dough together, just make sure not to overmix the dough too much, but enough for the dough to stick together to form cookie dough balls.
Divide the dough into 6 portions and form into large cookies. Place on the baking sheet.
Preheat the oven to 375 and while the oven is preheating, chill the cookie dough for at least 30 minutes. Whatever size you want the cookies to be, is the shape you should make them. They will stay thick, but will puff up some while they bake.
Bake the cookies for about 16-18 minutes. The outside of the cookies will be golden brown.
Let the cookies cool on the baking sheet for at least 5 minutes, before removing to a wire rack, as the cookies are still setting up.
The cookies need to cool before serving and are best served at room temperature for thick and chewy chocolate chip cookies.