Use a hand mixer to mix the brownie mix and canned pumpkin together thoroughly in large bowl.
Mixture willl be thick. Resist the urge to add water. Spread mixture in a greased 9X13 cake pan. If you desire thicker brownies, spread mixture in a smaller cake pan. I use a rare 7X11 cake pan and cut brownies 3 across and 5 down for a total of 15 brownies.
Bake according to pkg directions. Use a toothpick inserted in middle of brownies to test doneness. Toothpick should still be damp, but not caked with wet brownie. If brownies have pulled away from edge of cake pan, they are overdone.