Found this on the Joy of Cooking:
"Devonshire (or Devon) Cream is a clotted cream produced commercially in Devon, Cornwall, and Somerset England. It is a thick, rich, yellowish cream with a scalded or cooked flavor that is made by heating unpasteurized milk until a thick layer of cream sits on top. The milk is then cooled and the layer of cream is skimmed off. Clotted cream has 55-60 percent fat content and is so thick it does not need whipping."
They have lots of recipes and some have mascarpone in them...
So good, but yikes on the fat content.. We are on vacation when we have this so.. no calories.