This recipe was sent by Caroline of Good Website, makers of high quality oils, dressings, and mayo in the UK. All of their products are made from pure cold-pressed hemp seed oil. I have added alternate names where relevant for the ingredients.
First, put the hazelnuts in a food processor and process until finely ground. Add the rest of the dry ingredients and pulse until well mixed.
With the motor running, slowly pour in the oil until the mixture amalgamates. Tip into an oiled Swiss-roll tin (23x33cm/9×13″) and press down so it is level.
Prick all over with a fork then pop into the oven for 50-60 minutes. What you are looking for is a uniform pale golden all over, it wont be golden brown. It should also be a bit squidgy when it comes out the oven, it will harden as it cools.
After it comes out the oven, cut into squares then, after five mins or so, place onto a wire rack to cool.