Place sweet potatoes in a large stock pot, and fill it with water.
Add salt.
Bring to a boil over medium-high heat, and cook potatoes until soft when pricked with a fork, about 15 minutes.
Drain potatoes, and mash - either by hand or with a hand-masher (I mashed by hand).
Stir in orange zest and juice, marmalade, brown sugar, pineapple, 1/4 c. coconut oil, vanilla, and egg whites.
Spread mashed potato mixture into the bottom of a 9x13-inch baking dish.
Drizzle with remaining 1 tbsp. coconut oil.
Bake at 350 degrees for 20 minutes.
Meanwhile, in a small bowl, toss together macadamia nuts, coconut, and dried pineapple.
Remove casserole from heat. Sprinkle with mini marshmallows, then coconut mixture.
Return to oven for about 5 minutes, or until marshmallows are golden and melty, and coconut is toasted.
Serve warm.