In a large saucepan melt the marshmallows, oil, and butter until smooth. In a large bowl combine the popcorn, candies, and nuts. Add the marshmallow mixture and mix well. Press into a well greased 10-inch tube pan. Cover and refrigerate for 5 hours or overnight. Dip the pan in hot water for no more than 5 to 10 seconds to remove the cake from the pan. Slice with an electric or serrated knife.