Place dates in a bowl and cover with several inches of cool water until soft, 30 to 60 minutes. Drain, squeeze out extra liquid, and reserve. Chop dates into a thick paste.
Combine dates with cashews, vanilla extract, and salt in a bowl. Fold in chocolate chips. Press mixture firmly into a parchment paper-lined 8-inch baking pan until compact. Refrigerate until set, 1 hour to overnight.