To make your own puree, simply halve a pie pumpkin, remove seeds and strings, and place on a baking sheet. Bake at 350 degrees F (175 degrees C) until soft, 1 1/2 to 2 hours. Scoop flesh into a blender with 1 teaspoon oil; blend until pureed. One large pie pumpkin usually yields 2 cups. You can use it right away or keep it in the freezer until you're ready to use it.
If you are not a fan of cloves, omit cloves or reduce to get a less spicy bread. I use freshly grated nutmeg for the bread, also.