Process all ingredients into a fine sticky crumble in a food processor. Transfer to a parchment-lined baking dish (I used one that's roughly 6" x 4", but anything of a similar size will do). Press down firmly with the back of the spoon to compact the mixture. Then cover with a sheet of parchment and press down again with a flat-bottomed object to compact the mixture even more and to create an even top layer. Freeze for 5-6 hours of overnight. Cut into pieces and enjoy! Keep leftovers frozen.