Pumpkin puree is just canned pumpkin- the same you would use for pumpkin pie! It adds a creamy base that’s pure vegetable, so you don’t need as much cream or flour to make a thick, creamy base for the pasta sauce. It’s a little sweet, similar to butternut squash. Hope that helps! If you click the link on the ingredients list, you can see an example of the canned pumpkin puree :-)