The last ingredient you would expect to find in a delicious doughnut is bone marrow, but that’s apparently the secret behind this popular treat served at a New York doughnut shop.

The doughnut market has become very competitive in recent years, and businesses have to come up with something really special to get an edge. Some rely on crazy combinations to create hybrids like the popular Cronut, others cover their doughnuts with extravagant decorations like edible gold and sugar diamonds – see Donutopia, the $100 doughnut – and a few go the bizarre route. The treat we’re talking about today falls in the latter category.

The Doughnut Project, a fancy bakery in New York city, partnered with local butcher shop Hudson & Charles to create what we believe is the world’s first bone marrow doughnut. That sounds pretty disgusting, but the experienced bakers claim that bone marrow actually makes their hand-crafted, yeast-raised doughnuts more delicious. The chocolate pastry cream filling is whipped with roasted bone marrow that apparently enhances its richness and gives it a velvet-smooth texture. The unique treat is also glazed in clementine and sprinkled with orange-infused chocolate shavings.

The Doughnut Project, on Morton Street, first released the bone marrow doughnut during its Meat Week celebration (April 18th – April 22nd) as a limited edition product, but it was such a big hit with patrons that they decided to keep making it on order.

Grub Street reports that a single bone marrow doughnut costs $5.25, but you need to make sure it’s available before rushing to the shop.

Photos: The Doughnut Project