Preheat the oven to 350°F. Line a 9x13-inch metal baking pan with foil so that it extends over the edges then then grease the foil with cooking spray.
In the bowl of a stand mixer fitted with the paddle attachment, cream together the butter, brown sugar and sugar until light and fluffy, about 2 minutes.
Add the vanilla extract and salt, beating until combined, then add the eggs, one at a time, beating between each addition.
Add the baking powder and flour, beating until combined, then stir in 2 cups of the chocolate chips.
Spread the batter into an even layer in the prepared baking pan then top the batter with the remaining 1/4 cup of chocolate chips.
Bake the bars for about 30 minutes or until they are barely set in the center. (See Kelly’s Note.)
Remove the bars from the oven and immediately sprinkle them with sea salt. Allow the bars to cool completely in the pan before slicing and serving.