Spray a 9×13″ pan with non stick cooking spray; set aside (For faster cleanup, line with foil or parchment first.) Preheat your oven to 350 degrees.

Melt the butter in a large glass mixing bowl. Vigorously whisk in the brown sugar and granulated sugar until smooth.

Add the eggs and vanilla and whisk again.

Add the flour, salt, baking powder, and oats. Stir until all the flour is moistened.

Fold in the chocolate chips. (I like to save about 1/4 cup to sprinkle on top.)

Pour the batter into the prepared pan. It will be about the same consistency as brownie batter. Spread out evenly in the pan. Sprinkle the reserved chocolate chips over the top.

Bake at 350° for 25-30 minutes, or until edges are golden brown and middle is set. A toothpick inserted in the middle shouldn’t come out sticky, but moist crumbs are fine. To avoild dry bars, don’t over bake!

Let the bars cool for at least 15-20 minutes before serving. But they are much easier to slice after they have cooled completely for at least a couple of hours.