About.com's Pumpkin Jam recipe calls for pumpkin puree, spices, sugar, lemon juice and vanilla extract. Another good recipe uses a whole pumpkin instead of puree.
Make pumpkin jam by adding 1 29-ounce can of pumpkin puree, 3 tablespoons of lemon juice, 1 teaspoon of vanilla extract and 1 1/2 cups of sugar to a saucepan. Stir 1/2 teaspoon of cloves, 1/2 teaspoon of cinnamon, 1/4 teaspoon of ginger and 1/4 teaspoon of allspice to the pumpkin mixture, and bring all the ingredients to a boil on medium-high heat. Reduce the heat to low, and let the pumpkin mixture simmer for another hour before pouring the jam into jars. In order to preserve the jam for longer periods of time, use sterilized jars and seal on the lids once the jars cool.
For another recipe, peel an 8-pound pumpkin, remove the seeds and cut it into cubes. Press 2 whole cloves into 2 pumpkin pieces, and place the pumpkin into a saucepan along with 1 small cinnamon stick and 2 tablespoons of water. Bring the ingredients to a boil, and then reduce the heat, and simmer covered for 30 minutes. Once the pumpkin softens considerably, remove the cinnamon and cloves, and puree the cubes in a blender. Pour the pumpkin puree back into the saucepan along with 4 cups of sugar, and heat the mixture until the sugar melts.
Pour the pumpkin jam into jars for storage.