Whenever this orange starch is added to a dish, an element of sweet follows behind it — hence its name: sweet potato. The element of sweet in this recipe is cinnamon, and its presence results in a crispy, slightly sweet, nugget of sweet potato gnocchi. To keep this recipe from going down the dessert road, though, a few savory elements are included to keep it in check — a buttery sage-cream sauce and a dash of salty Parmesan cheese.
In a large bowl, mix together the sweet potato and ricotta. Add the Parmesan and mix well to incorporate. Next add the cinnamon, 2 teaspoons of salt, and 1 teaspoon of pepper, and stir well. Using a ½ cup measurer, slowly add the flour, mixing as you go, until you get a soft dough. (You want the gnocchi dough to be slightly sticky, but dry enough so you can work with it using your hands.)
Spread some flour out onto a work surface and a baking sheet. Divide the gnocchi dough into 12 equal portions. Roll each portion into a long rope, width of your choosing (I did ½-1 inch), and cut the rope into 1-inch gnocchi. Lay the gnocchi on the baking sheet while you roll out the rest of the dough.
Preheat the oven to its lowest setting for warm. Bring a large pot of salted water to a boil, and cook the gnocchi in batches (should be 2 batches total), about 4 minutes per batch. Drain the gnocchi and set aside.
Meanwhile, in a medium-sized saucepot, melt the butter over medium-low heat. Cook the butter until it starts to foam and milk solids start to bubble to the surface. The butter will begin to brown at this point; reduce the heat to low and add the sage. Using a medium-sized sauté pan, heat a little of the browned sage butter over high heat and fry the gnocchi in batches (about 3), until each gnocchi has a golden brown crust, about 5 minutes per batch. Add the gnocchi to a clean baking sheet and keep warm in the oven while you fry the rest of your batches, adding a little browned butter to the sauté pan as needed.
When all of the gnocchi has been fried and is warming in the oven, add all of the browned butter to the pan and increase the heat to high. Add the heavy cream, stir well, and bring to a boil. Reduce the heat to low and simmer until the sauce has thickened and coats the back of spoon, about 5 minutes. Serve the gnocchi in the sauce with a spoonful of Parmesan cheese.