For more than a decade, the buffalo-milk soft serve sold at the Palace Market drew acolytes from well beyond West Marin. Ultra-creamy and sumptuous, rich and airy yet almost chewy, it was, for many, the Platonic ideal of a swirled cone. 

But this week, unbeknownst to most, the beloved offering vanished, replaced by a version made with Jersey cow milk, the result of new ownership and a shifting supply chain.

The gelato first came…