Step 1

Place dates in a small bowl and add enough hot water to cover. Allow to sit for 10 minutes to soften.

Step 2

Preheat the oven to 350 degrees F (175 degrees C). Line 2 large baking sheets with parchment paper.

Step 3

Remove dates from water, reserving soaking liquid. Combine dates, walnuts, and vegetable oil in the bowl of a large food processor. Pulse several times until mixture forms a paste and no large chunks of dates remain; this may take several minutes. If mixture is too dry, add soaking liquid, 1 tablespoon at a time, until a paste-like consistency is reached. Add egg and vanilla extract; pulse to combine. Add oats, cocoa powder, baking soda, cinnamon, and salt. Pulse until combined, scraping down the sides of the bowl as necessary. Fold in chocolate chips; dough will be very sticky.

Step 4

Use a medium cookie scoop to place rounded balls of dough 1-inch apart on the prepared baking sheets. Press tops of dough down with damp fingers to flatten slightly.

Step 5

Bake in the preheated oven until cookies are just set, 13 to 15 minutes. Allow to cool on the baking sheets for 5 minutes before removing to wire rack to cool completely. Keep stored in refrigerator until ready to serve.