there pretty easy to make, and dont smell at all (besides a slight hint of chocolate).
basically, you make this by doing it the same way as you do with penutbutter. namley, spread nutella on 6 crackers (if you want to make 3 firecrackers). sprinkle however much bud you want on each (i'd say anything a half g or below). smush them together and make a sandwich. i sugest spreading a little nutella or penutbutter (maybe it can be like a resse's haha) around the edge to make sure it doesnt smell. wrap them lightly in foil and stick them in the oven for 20 minutes (i did about 18 and it still worked fine) at 350 degrees. cool them down and eat!