Preheat oven to 325 degrees. Prepare an 8 inch pan or line with foil.
Mix brown sugar and egg together, until it’s light and fluffy. Add in vanilla and melted butter, mix well
In a separate bowl combine the flour, baking soda and salt. Add the dry ingredients to the wet mixture and incorporate with a spatula. Fold in crushed Oreo's. Do not over mix.
Pour batter to the prepared pan. Bake for about 25-28 minutes. The top will be dry.