Cook sausage in a skillet over medium-high heat, breaking up large pieces, until it loses its pink color, about 5 minutes. Stir in tomatoes, oregano and 1/2 tsp. salt, reduce heat to medium-low and simmer until thick, stirring occasionally, about 20 minutes.
Combine ricotta, Parmesan and basil in a medium microwave-safe bowl.
Add noodles to boiling water; cook until just tender, 10 minutes or as package label directs. Just before noodles are done, microwave ricotta mixture on high for 30 seconds, stirring once.
Drain noodles well.
Spread 1 1/2 Tbsp. sauce on each of 4 dinner plates.
Place a noodle on top and spread with 1 1/2 Tbsp. cheese mixture. Top with 1 1/2 Tbsp. sauce. Repeat with noodles, cheese mixture and sauce, ending with a layer of sauce.
