Preheat your smoker to 400 degrees.

Place the bones on a tray and roast for 20 minutes.

Remove from the smoker and scrap the roasted bone marrow from the center of the bone and let cool for 10 minutes, reserve.

In a bowl combine, the roasted marrow, butter, salt, and parsley and mix together until fully incorporated; an immersion blender is recommended here.

Spread a sheet of plastic wrap across your counter and place the marrow butter in the center, in a straight line, and wrap tightly.

Place into the refrigerator to set and become firm.

Slice and enjoy as a garnish, or on hot toast, as needed.