In a glass measuring cup, combine the water, yeast and 1/2 teaspoon of sugar; set aside to foam for about 5 minutes. In the bowl of an electric mixer fitted with the paddle attachment, combine the mashed sweet potato, 1/3 cup of sugar, greek yogurt, milk, melted butter, egg, pumpkin spice, and salt.

Switch to the dough hook, and add the yeast mixture and 3 cups of the flour. Mix the dough on low and allow it to knead for about 6-7 minutes. If dough is still too soft, add more flour, 1 Tablespoon at a time, until dough just cleans the bowl, but is very soft. It should still stick to the bottom of the bowl.

Coat a large bowl with cooking spray and place dough in bowl. Seal tightly with plastic wrap. Place bowl in a warm place and allow dough to rise until doubled in size, about 2 hours.

In the meantime, line a 9-by-13-inch pan with aluminum foil and spray with nonstick cooking spray; set aside.

After dough has doubled in size, punch it down. Turn dough out onto a floured Silpat or floured countertop. With a rolling pin, roll it out to a 16-by-12-inch rectangle.

With a knife (or your fingers), spread butter evenly over the entire surface of the dough. Sprinkle the brown sugar over it, followed by the cinnamon. Lightly pat it down with your fingertips to help sugar adhere to dough. Roll dough tightly into a log, ending with the seam side down. Pinch the ends to seal.

Using plain, unwaxed dental floss (or a bench scraper), slice the rolls into 12 evenly-sized rolls. Arrange the rolls cut side down in the prepared baking pan. Cover tightly with plastic wrap.

Allow the rolls to rise again in a warm place until doubled in size, about 1 hour.

Place covered rolls in the refrigerator for up to 16 hours. Before baking, let the rolls sit at room temperature until they have nearly doubled in size, about 1 hour.

In the bowl of an electric stand mixer fitted with a paddle attachment, beat the butter and cream cheese together on medium speed for about 1 minute. Add the corn syrup, vanilla, salt, and powdered sugar and beat for 2 minutes. Scrape down sides of bowl, and beat for 1 more minute until light and fluffy.

Once rolls have baked, remove from the oven and immediately spread the cream cheese icing over the warm rolls, allowing the icing to melt into every crevice moistening the rolls even more! Serve immediately. Rolls are best eaten fresh, but will keep in an airtight container at room temperature for up to 5 days. Reheat leftover rolls for 10-15 seconds in the microwave before serving.