I make something similar with pumpkin puree from a can. I use 1/4 cup of pumpkin to 3 cups of flour and I use pumpkin pie spices too.

They come out terrific. I just made similar with pumpkin in a challah bread recipe. Terrific.

I'm sure if you use sweet potato instead of pumpkin, the recipe would just be as good.

Here is my recipe:

Pumpkin Soft Yeast Rolls
Recipe By : Unknown Internet Recipe
Makes 12 rolls

1/4 cup pumpkin puree
1 tsp vanilla extract
1 1/8 tsp dry active yeast (1/2 packet)
1 tbsp brown sugar
1/4 cup warm milk + 1/8 cup*
2 1/2 cups bread flour
1/8 cup butter, softened
1/2 tsp salt
1/2 tsp cider vinegar
1/8 tsp freshly ground nutmeg
1 egg, lightly beaten

Place ingredients in your machine according to manufacturer
directions. Place on dough cycle.

When dough is ready, place in a greased bowl and let rise in a draft-free area.

Spray muffin tins with butter-flavored cooking spray. Cut dough into 12 pieces and roll into balls. Place 6 balls in each muffin tin. Spray tops and cover with sprayed plastic wrap. Let rise once more in a draft-free area. When pleasantly puffed up, bake in a preheated 375F over for 15 minutes.

Let cool on a wire rack.

I hope this helps.
RisaG