Microwave the sweet potato until soft (about 7 minutes). Scoop out the flesh into a bowl.
Mix in ricotta, parmesan, and salt. Gradually add flour, kneading gently until dough forms. Do not over-knead.
Shape dough into a loaf, cut slices, and roll/stretch into ropes. Cut into 1-inch pieces. Toss with a little olive oil.
Boil gnocchi until they float. Drain. (Optional: Refrigerate or freeze for later).
Blanch broccoli rabe in boiling water for 1 minute, then shock in ice water. Drain.
Pan-fry gnocchi in butter until golden brown. Add broccoli rabe, minced garlic, sage leaves, and salt. Cook for a few more minutes.
Stir in heavy cream and Parmesan cheese until sauce lightly coats everything. Serve immediately!