Preheat oven to 350 degrees and spray one 9x5 inch loaf pan with cooking spray.
In a large bowl, combine flour, oats, brown sugar, baking powder, and salt. Mix until everything is well blended.
In a separate, smaller bowl, whisk together brown butter, egg, and buttermilk. Pour this mixture over the flour/oat mixture and stir with a large wooden spoon until just combined (a few streak of flour are ok!).
Fold in chocolate chips, then pour mixture into the prepared loaf pan. Bake at 350 degrees for 45-55 minutes, or until golden brown and a toothpick inserted in the center of the loaf comes out clean.
Let cool in pan for 10 minutes before carefully removing to finish cooling on a wire rack.