Preheat the over to 350 degrees. Combine the rolled oats, nuts, cinnamon, coconut flakes and cocoa powder in a large bow. Next pour in the butter, syrup and vanilla and combine well, then mix in the chocolate chunks. Transfer to a line baking sheet, press the mixture down with your hands so it's compressed. Bake for about 35 minutes. Let cool, then store in an air-tight container.