Put all ingredients except the chocolate chips and walnuts into a blender or food processor and blend until smooth.Once smooth, use a spoon to stir in half of the chocolate chunks (I like to reserve half to press into the tops once the cookies are formed)Place heaping spoonfuls of the mixture onto a baking tray lined with parchment paperUse a fork dipped in water (to prevent sticking) to flatten and shape the cookiesPress the rest of the chocolate chunks and the walnut chunks onto the tops of the cookiesBake at 350F for 10-15 minutes or until golden brown on the edges