Preheat the oven to 350 degrees. Toast walnuts on a rimmed baking sheet, tossing once, for 8-10 minutes, or until slightly darkened in color and fragrant. Allow to cool.

Meanwhile, place dates in a small bowl and cover with 12 cup hot water; soak for 10 minutes to soften.

In a blender, combine walnuts, dates with their soaking liquid, cinnamon, and salt until a coarse paste forms. Blend in the ice cream and 34 cup cracked ice until smooth. Divide the shake evenly between two glasses.