Preheat the oven to 350°F (175°C). Lightly grease a 9x13-inch baking pan with cooking spray or line it with parchment paper for easier removal and cleanup.

In a large mixing bowl, use an electric mixer to beat the softened butter, light brown sugar, and granulated sugar until the mixture is light, smooth, and creamy. This should take about 2–3 minutes.

Add the eggs one at a time, beating well after each addition. Stir in the vanilla extract until fully combined.

In a separate bowl, whisk together the salt, baking soda, baking powder, all-purpose flour, and rolled oats. Gradually add this dry mixture to the creamed butter and sugar mixture. Stir until just combined, being careful not to overmix.

Gently fold the chocolate chips into the dough using a spatula or wooden spoon. Ensure they are evenly distributed throughout the batter.

Spread the dough evenly into the prepared baking pan, pressing it gently with the back of a spatula to create a smooth surface.

Place the pan in the preheated oven and bake for 25–30 minutes, or until the top is golden brown and a toothpick inserted into the center comes out clean or with just a few crumbs.

Allow the bars to cool completely in the pan before cutting them into squares or rectangles. Cooling helps the bars set and makes slicing easier.