Add dry cake mix and pumpkin puree to a large mixing bowl. Using a wooden spoon, mix batter until just combined.
Using a hand mixer (or stand mixer) combine ingredients until well combined. It's a very thick batter, so a mixer is easier than doing it all by hand.
Line a muffin or cupcake tin with liners. This is optional, but does make clean-up much quicker and easier.
Use an ice cream scoop (a ladle or spoon will also work) to scoop batter into muffin tin. Try to get an even amount into each section, which should be filled about two thirds of the way full.
Bake for 18 to 20 minutes. Use a toothpick inserted into the center of the muffin to test. If it comes out with just a few moist crumbs, the muffins are ready. If there's wet batter on the toothpick, let them bake a minute or two longer, testing afterwards.
Remove muffins from the muffin tin and let cool completely on a wire rack.
Notes
These two ingredient pumpkin muffins aren't super sweet, so you can top with icing or frosting of your choice.One cup of chopped nuts like pecans or walnuts are a great addition. So are dried cranberries if you have nut allergies.Try different kinds of cake mixes to change up the flavor. Chocolate cake mix as well as vanilla cake mix will work nicely. Carrot cake mix is also a great way to get that fall flavor if spice cake mix is sold out.