Mix the sugar, salt, cinnamon, sweet potato, and eggs in a mixer with the hook attachment. When combined mix in the buttermilk and butter. Sprinkle the yeast over the mixture and add the flour. Mix for 5-8 minutes. The dough will be sticky. Place the dough in an oiled bowl, cover, and proof for 1 1/2 hours or doubled in size.
On an oiled surface, roll the dough into a 10x16 rectangle. Fill the rolls and roll into a 16 inch log. Cut the log into 6 portions. Place the rolls into a greased 8x8 pan, cover, and proof for 30 minutes.
Preheat the oven to 350 degrees. Bake the rolls for 25-30 minutes. Cool the rolls and remove from the pan. Ice with cream cheese frosting, sprinkle with streusel, and serve.