Place the probed salmon on the plank in the grill and close the lid.
Set the high-temp alarm on the meat channel of your Smoke X or the ThermoWorks app to 125°F (52°C).
Cook!
While the salmon cooks, prepare your compound butter by mixing the butter, lemon zest, fresh dill, and some black pepper to taste together. You can do this in a mixer or just mash it all together with your hands. Set aside at room temperature.
When the high-temp alarm sounds, verify the doneness with your Thermapen ONE. Make sure no part of the salmon is cooler than 125°F (52°C).
Dot the salmon with the softened compound butter (you won't use all of it), remove it from the grill, and serve it up!
Notes
Note: how to cook cedar plank salmon in the oven
If you want to cook this dish but don't have a grill, no problem. Prepare the plank and the salmon exactly as you would for the grill, but cook it in a 375°F (191°C) oven. Place the plank on a rimmed baking sheet to prevent any stray juices from dripping in your oven.