Blend roughly equal parts hazelnut butter and raw cocoa powder with a dash of your choice of sweetener. Use a fork and just keep mixing until combined. It will be a thick paste. (Notice I'm not suggesting you serve it to guests. This is a late night kind of thing.) Pour a handful of frozen blueberries in the bowl, wait a few minutes until the blueberries just begin to soften, and enjoy.
So I'm just about to post this and Ryan told me I'm basically making a whole foods Nutella. So go figure.