In a large mixing bowl, mix together the cake mix, flour, oil, and eggs. The batter will be very thick, so you may need to use either the paddle attachment or your hands to get it to come together. Stir in the chips and nuts. Shape the dough into a rectangle about 15x4 inches on an ungreased baking sheet. If you've used the white chips, make sure they're all nestled in the dough and not sticking out on top, otherwise they may turn brown.