Preheat oven to 350 degrees F (175 degrees C). Grease a 9x13 inch pan.
Combine the butter, brown sugar, flour, baking soda, salt and rolled oats. Press 2 cups of the mixture into the bottom of the prepared pan. Spread the preserves over the top and sprinkle with the remaining crumb mixture, gently pressing crumbs into jam.
Bake at 350 degrees F (175 degrees C) for 35 to 40 minutes. Allow to cool before cutting.