In a large bowl, whisk together cake mix, water, oil, and eggs. I prepared it according to package directions. Just buy a chocolate cake mix, and prepare it according to package directions for a 9x13. Cool completely.
Break up the cake into small cubes and coarse crumbs, and divide into 4 equal portions.
In a large bowl, whisk together pumpkin, cinnamon, pumpkin pie spice, milk, and instant pudding mixes til smooth.
In a large bowl, fold cocoa powder into whipped topping until combined.
To assemble the trifle, from bottom to top, it will be as follows: one portion cake crumbs, half the pudding mixture, one portion cake crumbs, 1 cup chocolate chips, half the whipped topping, one portion cake crumbs, remaining pudding, remaining cake crumbs, remaining 1 cup chocolate chips, remaining whipped topping. Got it?? :)
That's it! Store in refrigerator. Spoon into dishes to serve!