Add all ingredients except chocolate chips to a food processor or blender. Blend until smooth. Slowly stir in the chocolate chips (reserve a few chips for the top of the cookie).
Pour batter into an 8-inch cast iron skillet. Bake in the oven for 35-45 minutes or until a toothpick inserted into the center comes out clean. The cookie is very soft and gooey, it will not be a firm cookie.
For the drizzle, whisk together maple syrup and tahini until well combined. Drizzle on top of cookie.