Step 1

Prick a sweet potato all over with a sharp knife and microwave until very soft, 5 to 7 minutes. Let sit until cool enough to handle.

Step 2

Cut potato in half and scoop flesh into a bowl. Mash or blend until smooth. Add ricotta cheese, egg, kosher salt, and cayenne; mix with a spoon until smooth and combined. Stir in flour until mixture comes together into a sticky ball of dough, adding more flour as needed.

Step 3

Transfer to a floured surface and knead gently, adding flour as needed, until no longer sticky. Divide into 8 portions. Roll into ropes about 1/2-inch thick, using flour as needed. Dust ropes with flour and cut with a bench scraper into 1/2-inch pieces. Transfer pieces onto a sheet pan and let dry on the pan for 15 to 20 minutes, or refrigerate until needed.

Step 4

While gnocchi dry, bring a large pot of salted water to a boil.

Step 5

Cook bacon in a skillet over medium heat until browned and crisp, 7 to 10 minutes. Add butter and cook until lightly toasted, 2 to 3 minutes. Turn off heat and stir in rosemary. Reserve until needed.

Step 6

Stir gnocchi into the pot of boiling water and cook until they float to the top, 3 to 4 minutes. Use a slotted spoon to transfer cooked gnocchi to the sauce.

Step 7

Heat over medium to medium-high heat, coat with sauce, and season with salt. Turn off heat and stir in 1 tablespoon Parmigiano-Reggiano cheese. Transfer to a warm serving bowl and top with additional Parmigiano-Reggiano.