Preheat the oven to 350°F. Grease and flour a 10" tube or Bundt pan., In a large bowl, beat eggs until foamy., Stir in pumpkin, vegetable oil and bran cereal; combine well., In another bowl, sift together flour, baking soda, baking powder, salt, sugar, and spices., Add to wet ingredients and mix gently, until just combined., Stir in nuts and chocolate chips., Spoon the batter into the prepared pan., Bake in preheated 350°F oven for 70 minutes, or until a cake tester inserted in the center comes out clean., Remove from the oven and cool the cake in the pan for 10 minutes, then remove from the pan and cool completely on a rack before slicing., Store, loosely covered, at room temperature for 5 days, or freeze for up to 3 months.