Preheat the oven to 350 and grease a 10" skillet with butter or shortening.
While the oven is preheating, in a stand mixer cream together the butter, sugars, vanilla, and egg. Beat until the mixture is light and fluffy.
In a separate bowl, whisk together the flour, salt, baking powder, and baking soda.
Add about a third of the dry ingredients into the wet ingredients, and mix until combined. Repeat two more times with the rest of the dry ingredients. Mix until combined.
Fold in the chocolate chips.
Press the dough into the skillet.
Bake in a 350 degree oven for 15-20 minutes, or until the edges of the cookie are golden and the center is set but slightly soft.
Serve with ice cream.
Notes
* We used an all purpose gluten free flour blend, but you can make this cookie with regular all purpose flour as well.