Prepare the damsons as you fancy, either by freezing or pricking with a clean needle; I often just pick them here and there then freeze, making a new batch of vodka every time I reach the magic 500g mark.
Place the damsons in a large kilner jar, then add the vodka, sugar and spices before shaking well.
Leave the jar by the kettle for five days; every time you make a cup of tea, give the jar a gentle shake to help the sugar dissolve.
On the sixth day, fish out the cardamom pods, cinnamon sticks and vanilla pod with a clean fork, then put the jar away in a dark cupboard for at least three months… but twelve is better!
Strain the vodka through a coffee filter or fine muslin then decant into pretty bottles (it might take overnight for the liquid to drip through a coffee filter but the result will be a beautifully clear berry colour). The left-over infused damsons can be stoned and added to fruit crumbles, chopped and served with good quality ice cream or mixed with melted dark chocolate to make boozy little petit fours.