Preheat your oven to 350°F (175°C).

Grease a 9x13 inch baking pan with butter or cooking spray.

In a mixing bowl, cream together the brown sugar, granulated sugar, and softened butter until light and fluffy.

Mix in the milk and vanilla extract until combined.

In another bowl, whisk together the flour, baking soda, and salt.

Gradually add the dry mixture to the wet ingredients, mixing until just combined.

Gently fold in the rolled oats and chocolate chips.

Pour the batter into the prepared baking pan and spread it evenly.

Bake for 25-30 minutes or until the edges are golden brown and a toothpick inserted in the center comes out clean.

Let the bars cool completely in the pan before cutting them.