What did I do wrong? The oil from the nuts and chocolate ganache made this all lumpy and liquidy. Not creamy at all. Very disappointed:(

Perhaps your equipment is an issue? I would definitely use a blender vs a food processor. Once I purchased a Vitamix blender, I was amazed at the difference it made vs my older waring blender.

I don't have an answer to your question, but it appears others have had similar troubles. I've made the version from the most recent Cook's Illustrated, which is quite similar to this one: https://food52.com/recipes/11365-nochella . The CI version has you boil the nuts in water with baking soda to help remove the skins before roasting, and calls for 1/3 cup cocoa powder instead of 1/4 cup. It also adds 1/8 tsp salt. The CI recipe called for only 2 T hazelnut oil, but I found I needed to add more. The end product is fantastic -- like a richer version of Nutella w/o the slightly greasy mouth feel.

Junco, I read over the recipe and I have several idea. 1. when you were making the ganache and melting the chocolate it is really important to know that If melted chocolate gets any water in it, the chocolate will seize up and become clumpy. If chocolate gets to hot when melting it can do the same thing. Janco, you might try putting every thing back into a sauce pan add a little cream and butter and heat the pan slowly and stir..It is worth a try. Good luck, Julie B