Preheat oven to 400°. Place sweet potatoes on baking pan and bake for 50-55 minutes, or until soft. Let sit until cool enough to handle.
Whisk tahini, peanut butter, soy sauce, honey, lime juice, garlic, and ginger in a bowl. Add water a little at a time to achieve your preferred consistency.
Slice potatoes in half long-wise and scoop out potato into medium bowl, leaving about 1/2" potato layer. Set skins aside.
Add butter, then sauce a bit at a time to potatoes, reserving about 2 tsp to brush over the tops. Mix until well combined.
Spoon mixture back into the potato skins, brush tops with sauce, and bake for 15-20 minutes, or until light golden brown. Sprinkle with peanuts and serve.