Transfer figs to a large bowl. Add lemon juice and stir to spread evenly. Cover and leave to marinate on room temperature for 45-60 minutes.

In a large pot bring sugar, vanilla extract and water to a boil on high. Stir frequently with a wooden spoon. Add figs and lower temperature. Stir again. 

Simmer on low for 45-50 minutes. Stir frequently and thoroughly every 3-4 minutes. Remove any foam that forms on top. 

Using a stick blender, carefully blend jam down to a desired consistency. Add rum and stir well. (Optional) If you’re using walnuts and ginger (or cinnamon) add now. 

Simmer an additional 5 minutes or so. Check for done-ness by making a line with your spatula on the bottom of the pot. Jam is done when it separates then connects again easily. 

Heat oven to 390°F. About 20 minutes before jam is done, wash and dry jars you’ll be using to store the jam in. Place them on a baking sheet and heat in oven for 15 minutes. (This sterilizes them.)  

Keeping your hands safe with a kitchen towel or a mitten, carefully transfer jam into hot jars. Fill jars to the top. Using a teaspoon push the jam all the way down to get the air bubbles out, and add more jam if able. Close lids tightly and flip jars upside down for sealing. 

When jars with fig jam have cooled down, flip them up and transfer to a cool, dark place (or fridge). Once you open a jar transfer to fridge.