Rinse your scallops under cold water, remove the abductor muscle and place them on a paper towel lined baking sheet. Then place another layer of paper towels on top of the scallops. Let scallops dry like this for 20 minutes.
Light your grill and set it up for high direct heat. Over top of the heat source, place a cast iron griddle surface. You can also use a cast iron pan and cooktop.
While the scallops are drying, and the grill is preheating, add all the ingredients for the cajun seasoning into a shaker bottle.
In a small mixing bowl, mix together two tablespoons of cajun seasoning with one stick of room temperature butter and diced shallots. Set aside.
Evenly coat the scallops with avocado oil and season them on both sides with the one tablespoon cajun seasoning.
With the griddle surface preheated, evenly coat with two tablespoons of avocado oil and place the scallops on the hot surface. Allow them to sear for two to three minutes per side, until internal temperature reaches 115°F.
Remove from the grill, top the hot scallops with room temperature bayou butter and allow it to melt. Then garnish with parsley and serve.