In a saucepan, combine pumpkin puree, brown sugar, cinnamon, nutmeg, cloves, ginger, and salt.

Cook over medium heat, stirring frequently, until the mixture starts to bubble.

Reduce heat to low and simmer for about 45 minutes, stirring occasionally.

Add apple cider vinegar and lemon juice, and cook for an additional 5-10 minutes.

Remove from heat and let cool slightly before blending until smooth.

Transfer to a jar and refrigerate.