Preheat smoker to 250°F. Wash and dry the sweet potatoes. Pierce with a fork on all sides and the drizzle with olive oil, rubbing all of the skin. Season with 1 teaspoon salt.
Smoke the sweet potatoes for 2 hours or until you can pierce with a fork.
While sweet potatoes or cooking, make garlic sage butter. Melt butter in small skillet and cook until it is starting to brown, about 2-3 minutes. Add garlic, sage and ¼ teaspoon salt and cook for 30 seconds. Remove from heat and set aside.
When the sweet potatoes are done, split open with a knife and fluff the insides. Top with some of the garlic sage butter.
Notes
Use a fruit wood for a subtle smoke flavor like cherry or apple.
If you're short on time, you can smoke at 350°F for about 45 minutes, but you'll have less smoke flavor.
Cooked sweet potatoes should have fork easily pierce through it.
You will know the brown butter is ready when there is a nutty aroma and there are lightly browned specks on the bottom of the pan.