Preheat the oven to 350 degrees F (or 180C).
Melt butter in the microwave then let it cool.
Whisk butter with white sugar, vanilla and 1 egg.
Add flour, baking powder, baking soda, salt and brown sugar. Mix well.
Stir in chocolate chips.
Pour batter in a prepared baking dish (I used a parchment paper lined 9x9 pan).
Bake for approximately 30-35 minutes.
Remove from the oven and top with an additional 2 Tbsp of chocolate chips. Let cool before slicing.
ENJOY!