Put the pears in a large heavy-based saucepan. Add the malt syrup, lemon and cinnamon and toss until combined.
Let the fruit marinate for 30-40 minutes then start to cook it over medium heat, stirring occasionally.
As soon as the pears start to liquify, change the heat to low, add the thyme and simmer for 40-50 minutes, or until the jam has thickened, stirring constantly to keep from sticking to the pan.
When the jam has reached setting point, pour it into individual jars.
Let cool before covering each jar with a tight-fitting lid. Store in a very cool, dry, dark spot.