Preheat oven to 350 and lightly grease a 9x13 in pan.
In a large bowl, combine the 1st 6 ingredients. Mix well. Spread into the prepared pan.
Sprinkle cake mix over the top of the mixture and pat down. Sprinkle the chopped pecans over the cake mix then drizzle the melted margarine on top.
Bake for 60-80 minutes or until done. It will depend on your oven so check after 60. Let it cool completely then turn on onto a sheet or cake stand and top with the cool whip then maybe a little more chopped pecans for decor.
*Note: For a potluck- turn cake onto a travel cake tray then put the lid on and go. Works perfectly.