1. Preheat over to 425 and cook bacon on a baking sheet until crisp, about 10 minutes.

2. Cook pasta in salted boiling water until done. Reserve one cup pasta water before draining.

3. Heat olive oil in skillet over medium high heat. Add sweet potato and garlic and cook, stirring occasionally, until potato is tender.

4. Add potato mixture and cheese to pot of drained pasta and cook over medium-low heat, adding pasta water in small increments, until cheese is melted and the sauce is a nice light consistency. Only use as much water as you need.

5. Add bacon and rosemary (saving back a little rosemary for garnish) and toss again.

6. Divide among four plates and sprinkle some more cheese and rosemary on top, and grind some fresh black pepper on top. Serve at once.