Stir together cookie crumbs, flour, baking powder, cinnamon and salt in a large mixing bowl. In a medium bowl, whisk together brown sugar and eggs. Stir in buttermilk and vanilla. Pour over dry ingredients and stir just until incorporated. Stir in melted butter, then chocolate chunks.
Preheat waffle iron and lightly spray with cooking spray. Spoon about 1/2 cup batter into waffle iron and spread over the grids with a wooden spoon. Close the lid and bake until the waffle is golden brown and set.
Serve immediately, or keep warm on a rack in a preheated 200-degree oven. Serve with maple syrup, or make your own Fluffy Orange Butter, Maple Coffee Butter or Cinnamon Sugar Butter.
Makes about 8 waffles.
Recipe used with permission from Janine MacLachlan, chef and owner of The Rustic Kitchen cooking school in Chicago, IL.