To resurrect an 1-2 year old English Christmas dark fruitcake, I removed the icing and marzipan, infused it liberally with whiskey liqueur - then cut it into cubes. I then served it with cocktail sticks and a dip of pure Advocaat. It was a great success, but the tasty dip should have been thicker like a light custard.
So the question is: How can I thicken it while still keeping 17% alcohol. If I add cornflour, I need to heat it up to thicken. But alcohol boils at 78degC which may not be hot enough for the cornflour.