Fire up your grill for direct and indirect cooking.
Place the plank rough-side down over high direct heat. Let the plank get nice and hot, smoke and even get a bit charred. Move to indirect heat.
Add the hot dogs, onions, and bacon to the plank. Close the grill and let the ingredients cook for 15 minutes. Make sure you have the heat high enough to make the plank smoke but don't let it catch on fire. I keep a spray bottle full of water nearby just in case...
Remove the hots dogs to a plate.
Transfer the onions and bacon to a skillet on the stovetop over medium-high heat or use a small cast iron skillet on your grill since it's already nice and hot.
Cook the onions and bacon until the bacon is crisped and the onions are done.
Meanwhile toast the buns as desired.
Serve dogs on buns topped with the bacon and onions and your favorite condiments.