Place the ground beef, sausage, bread crumbs, jalapeños, onions, buttermilk, eggs and Jeffs' original rub into a large bowl and combine.
Remove the meatloaf mixture and form it into a loaf that is rectangular in shape and about 2 to 3 inches thick on top of a wood plank.
This can be made in advance if you wish and put into the fridge until you are ready to smoke it.
Set up your smoker for cooking at 225-240°F with indirect heat. If your smoker has a water pan, fill it up.
Place the plank with the meatloaf on the smoker grate and cook with smoke until the internal temperature of the meatloaf reads 160°F as measured by a digital probe meat thermometer.
About 30 minutes before the meatloaf is finished cooking, add a layer of Jeff's original barbecue sauce to the top and sides of the meatloaf.
When the meatloaf is finished cooking, remove it from the smoker.
Let it rest for about 10 minutes before serving.
Slice into ½ inch pieces and enjoy!