In a food processor, add the first eight ingredients. Blend until a smooth mixture forms. You may have to stop the food processor and scrape down the sides a few times until it mixes well.
In a spice grinder, pulse together the raw almonds, cashews, walnuts and pecans until they are broken into smaller pieces (eg. each nut should be broken up into 4-5 smaller pieces to be able to bite into, as it will be hand-mixed into the cake). They shouldn't be so fine that they become a powder, but just into smaller chunks. You can also do this with a knife but it will take longer.
Add the broken nuts, along with the last four ingredients, into the food processor mixture. Do not blend it, but just mix it in with a spatula, until all the add-ins are evenly mixed.
Line an 8x8 inch baking tray with parchment paper.
Add the mixture evenly into the tray, pressing it down firmly.
Place in the refrigerator for at least one hour.
After an hour, use a knife run under hot water to ensure a clean cut. Cut it into 12 servings.
Enjoy it chilled, or bring to room temperature before serving.